Semiconductor device and method for manufacturing the same

ABSTRACT

An electronic device includes: a substrate having first and second surfaces, wherein the first surface is opposite to the second surface; a first electronic element mounted on the first surface of the substrate; a second electronic element mounted on the second surface of the substrate; and a resin mold sealing the first electronic element and the first surface of the substrate. The resin mold further seals the second electronic element on the second surface of the substrate. The second surface of the substrate has a portion, which is exposed from the resin mold. The second electronic element is not disposed on the portion of the second surface.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on Japanese Patent Applications No.2007-323065 filed on Dec. 14, 2007, No. 2008-201839 filed on Aug. 5,2008, and No. 2008-213862 filed on Aug. 22, 2008, the disclosures ofwhich are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a semiconductor device and a method formanufacturing a semiconductor device.

BACKGROUND OF THE INVENTION

An electronic device is proposed in Patent Documents 1, 2, and 3, forexample. A first electronic component is mounted on a first surface of aceramic substrate. A metal plate such as a heat sink is bonded to asecond surface opposite to the first surface of the ceramic substrate. Amolding resin seals the ceramic substrate and the first electroniccomponent so as to expose a surface opposite to a bonding surface of themetal plate.

Patent Document 1: JP-2003-7933-A

Patent Document 2: JP-2006-147918-A

Patent Document 3: JP-2006-222406-A corresponding to U.S. Pat. No.7,294,912

Conventionally, as mentioned above, electronic components are mounted onone surface of the ceramic substrate. The inventors came up with theidea of mounting electronic components on the other surface opposite toa metal plate of the ceramic substrate. This makes it possible toimprove the density of mounting components on a substrate. We examinedprototypes based on that idea.

FIG. 30 is a schematic sectional view showing an electronic device madeby the inventors as a proto type according to a related art. In FIG. 30,a metal plate 50 is arranged opposite to one surface of a ceramicsubstrate 10 via an adhesive J1. The ceramic substrate 10 and the metalplate 50 are bonded to each other.

A first electronic component 20 is mounted on a first surface of theceramic substrate 10. A second electronic component 30 is mounted on asecond surface. A molding resin 80 such as epoxy resin is used to sealthe ceramic substrate 10, the first electronic component 20, and themetal plate 50. A bonding surface of the metal plate 50, that is, thesurface opposite to the ceramic substrate 10, is exposed from themolding resin 80.

A depressed portion 50 a is provided at a portion of the bonding surfaceon the metal plate 50 corresponding to the second electronic component30. The second electronic component 30 is inserted into the depressedportion 50 a. The second electronic component 30 in the depressedportion 50 a is sealed with the adhesive J1.

The adhesive for bonding the ceramic substrate 10 to the metal plate 50is, for example, silicon resin that is soft and flexible and shows asmaller Young's modulus than the molding resin 80. When the depressedportion 50 a is not provided, the adhesive J1 becomes thicker by theheight of the second electronic component 30. There may be a possibilityof increasing thermal resistance and finally decreasing radiationperformance.

A general method is used to manufacture such electronic device. Theelectronic components 20 and 30 are mounted on the ceramic substrate 10.The metal plate 50 is bonded to the ceramic substrate 10 and is placedin a die. The resin is injected into the die for sealing. This packageshows a large mold structure including the ceramic substrate 10. Arelatively large pressure (e.g., 7 to 20 MPa) is needed to inject theresin so as to completely fill the molding resin.

The metal plate 50 is bonded to the substrate 10 and is partiallyexposed from the molding resin 80. The exposed surface of the metalplate 50 is pressed against the die during the mold process. A moldpressure of the resin is applied to the ceramic substrate 10 from theone surface.

According to the above-mentioned prototype, the soft adhesive J1 isfilled in the depressed portion 50 a of the metal plate 50. Theabove-mentioned mold pressure may easily warp the ceramic substrate 10so as to depress a portion of the ceramic substrate 10 corresponding tothe depressed portion 50 a toward the depressed portion 50 a. Thewarpage of the substrate 10 may cause the substrate 10 to crack.

The above-mentioned problem may apply to not only ceramic substrates butalso resin substrates such as printed substrates and metal substrates.It may be well necessary to consider a substrate crack due to theabove-mentioned mold pressure applied from one surface of the substratealso in the case of half molding the substrate without bonding the metalplate to the substrate. The above-mentioned problem is considered to becommon to electronic devices that half mold electronic components onboth surfaces of the substrate.

Further, Patent Document 4 proposes a conventional car electroniccircuit device. Specifically, Patent Document 4 proposes a device thatis mounted with circuit elements on the surface side of a substrate. Alead frame island is bonded to the reverse side of the substrate. Thesubstrate and the circuit elements are sealed with sealing resin so asto expose the island.

Such structure includes the substrate bonded with the island on thereverse side and is placed at a molding die including an upper mold anda lower mold. A resin is poured from a plunger into the molding die tomold the resin. The structure is so formed that the substrate issandwiched between the sealing resin and the island.

Patent Document 4: JP-2001-352185 A

According to the conventional technology, however, the substrate isstructured to be sandwiched between the sealing resin and the island.The substrate surface is subjected to a molding pressure during resinseal. At this time, the resin molding pressure may deform the substratedepending on a substrate state before the resin seal.

Specifically, the substrate deformation is caused by a void contained inan adhesive for bonding the island to the reverse side of the substrate.The void occurs when the adhesive is applied to the island or thereverse side of the substrate, the adhesive is hardened by hardeningreaction gas, or vapor contained in the adhesive expands.

Let us consider the resin seal using the resin that contains voids asmentioned above. The lower mold presses the island. The resin moldingpressure is applied to the island from the surface of the substrate. Theadhesive is sandwiched between the island and the reverse side of thesubstrate. A strong compression force is applied to the adhesive.Accordingly, the reverse side of the substrate is subjected to a strongrepulsive force.

Part of the adhesive corresponding to the void contains no adhesive andtherefore causes no repulsive force of the adhesive. On the other hand,the substrate surface is subjected to a molding pressure of the resin.Unbalanced forces are applied to both sides of the substrate. An excessforce is applied to the substrate and components mounted thereon. Thiswarps the substrate, deforms the components, or causes a componentfailure.

Just a single void, when it is considerably big, may cause theabove-mentioned phenomenon. Multiple voids, when gathered, may cause thesame result.

As mentioned above, the substrate is deformed due to occurrence of avoid when the substrate is so structured as to be sandwiched between thesealing resin and the island. Similarly to the void, the substrate isdeformed when resin seal is applied so as to expose the reverse side ofthe substrate.

In this case, a gap is formed between the lower mold and the substrate.The gap functions like a void. As mentioned above, unbalance forces areapplied to both sides of the substrate to deform or damage thesubstrate. In particular, a ceramic substrate is easily bent at theouter edge. The bent outer edge of the ceramic substrate is pushedtoward the lower mold and is destroyed due to a molding pressure of theresin.

SUMMARY OF THE INVENTION

In view of the above-described problem, it is an object of the presentdisclosure to provide a semiconductor device. It is another object ofthe present disclosure to provide a method for manufacturing asemiconductor device.

According to a first aspect of the present disclosure, an electronicdevice includes: a substrate having first and second surfaces, whereinthe first surface is opposite to the second surface; a first electronicelement mounted on the first surface of the substrate; a secondelectronic element mounted on the second surface of the substrate; and aresin mold sealing the first electronic element and the first surface ofthe substrate. The resin mold further seals the second electronicelement on the second surface of the substrate. The second surface ofthe substrate has a portion, which is exposed from the resin mold. Thesecond electronic element is not disposed on the portion of the secondsurface.

According to this configuration, it is possible to prevent the substratefrom cracking during a mold process. Thus, a molding resin stressapplied on the substrate from one surface of the substrate during a moldprocess is reduced.

According to a second aspect of the present disclosure, an electronicdevice includes: a ceramic substrate having first and second surfaces,wherein the first surface is opposite to the second surface; a firstelectronic element mounted on the first surface of the ceramicsubstrate; a metal plate bonded to a first portion of the second surfaceof the ceramic substrate via an adhesive; a second electronic elementmounted on a second portion of the second surface of the ceramicsubstrate; and a resin mold sealing the ceramic substrate and the firstand second electronic elements so as to expose the metal plate. Thefirst portion of the second surface is different from the second portionof the second surface.

According to this configuration, it is possible to prevent the ceramicsubstrate from cracking during a mold process.

According to a third aspect of the present disclosure, a manufacturingmethod of an electronic device includes: mounting a first electronicelement on a first surface of a ceramic substrate; bonding a metal plateto a first portion of a second surface the ceramic substrate, whereinthe second surface is opposite to the first surface; mounting a secondelectronic element on a second portion of the second surface of theceramic substrate, wherein the second portion of the second surface isdifferent from the first portion of the second surface; and sealing theceramic substrate and the first and second electronic elements with aresin mold so as to expose the metal plate. The metal plate is bonded tothe ceramic substrate via an adhesive. The second portion of the secondsurface is different from the first portion of the second surface, andthe first and second electronic elements are simultaneously sealed withthe resin mold.

According to this configuration, it is possible to prevent the ceramicsubstrate from cracking during a mold process.

According to a fourth aspect of the present disclosure, a manufacturingmethod of an electronic device includes: mounting a first electronicelement on a first surface of a ceramic substrate; bonding a metal plateto a first portion of a second surface of the ceramic substrate, whereinthe second surface is opposite to the first surface; mounting a secondelectronic element on a second portion of the second surface of theceramic substrate, wherein the second portion of the second surface isdifferent from the first portion of the second surface; sealing theceramic substrate and the first electronic element with a first resinmold so as to expose the metal plate; and sealing the second electronicelement with a second resin mold at a molding temperature equal to amolding temperature of the first resin mold. The second resin mold hasYoung's modulus equal to or larger than 100 MPa, and the metal plate isbonded to the ceramic substrate via an adhesive.

According to this configuration, it is possible to prevent the ceramicsubstrate from cracking during a mold process.

According to a fifth aspect of the present disclosure, a manufacturingmethod of an electronic device includes: mounting a first electronicelement on a first surface of a ceramic substrate; bonding a metal plateto a first portion of a second surface of the ceramic substrate, whereinthe second surface is opposite to the first surface; mounting a secondelectronic element on a second portion of the second surface of theceramic substrate, wherein the second portion of the second surface isdifferent from the first portion; sealing the ceramic substrate, themetal plate and the first and second electronic elements with a resinmold; and removing a portion of the resin mold to expose the metalplate. The metal plate is bonded to the ceramic substrate via anadhesive.

According to the above configuration, it is possible to prevent theceramic substrate from cracking during a mold process.

According to a sixth aspect of the present disclosure, an electronicdevice includes: a substrate that includes a first surface and a secondsurface opposite to the first surface; an electronic element mounted ona first portion of the first surface of the substrate; a metal platebonded to the second surface of the substrate so as to expose a secondportion of the second surface of the substrate opposite to theelectronic element; and a resin mold that seals the first surface of thesubstrate and seals the second surface of the substrate so as to exposethe metal plate. The resin mold sandwiches the first portion of thefirst surface and the second portion of the second surface of thesubstrate.

According to the above device, it is possible to prevent deformation ofthe substrate and the electronic element. Thus, a structure is providedsuch that the structure prevents the substrate from being deformed dueto a molding pressure of resin mold.

According to a seventh aspect of the present disclosure, an electronicdevice includes: a substrate that includes a first surface and a secondsurface opposite to the first surface; an electronic element disposed inthe substrate; wherein the first surface includes a first portioncorresponding to the electronic element; a metal plate bonded to asecond surface of the substrate so as to expose a second portion of thesecond surface of the substrate opposite to the first portion of thefirst surface; and a resin mold that seals the first surface of thesubstrate and seals the second surface of the substrate so as to exposethe metal plate. The resin mold sandwiches the first portion of thefirst surface and the second portion of the second surface of thesubstrate.

According to the above device, it is possible to prevent deformation ofthe substrate and the electronic element. Thus, a structure is providedsuch that the structure prevents the substrate from being deformed dueto a molding pressure of resin mold.

According to an eighth aspect of the present disclosure, an electronicdevice includes; a ceramic substrate having a first surface and a secondsurface opposite to the first surface; an electronic element is mountedon the first surface; and a resin mold that seals the first surface ofthe ceramic substrate and seals the second surface of the ceramicsubstrate so as to expose an inner portion of the second surface. Thefirst surface has an outer edge, and the second surface has an outeredge, and the resin mold sandwiches the outer edge of the first surfaceand the outer edge of the second surface.

According to the above structure, it is possible to prevent deformationof the ceramic substrate and the electronic element.

According to a ninth aspect of the present disclosure, an electronicdevice includes: a ceramic substrate having a first surface and a secondsurface opposite to the first surface; an electronic element mounted onan inner portion of the second surface; and a resin mold that seals thefirst surface of the ceramic substrate and seals the second surface ofthe ceramic substrate so as to expose the electronic element and theinner portion of the second surface. The first surface has an outer edge(391 a), and the second surface has an outer edge (392 b), and the resinmold sandwiches the outer edge of the first surface and the outer edgeof the second surface.

According to the above structure, the electronic element inappropriatefor molding can be prevented from characteristic degradation or failuredue to a molding pressure of the resin mold.

According to a tenth aspect of the present disclosure, a manufacturingmethod of an electronic device includes: mounting an electronic elementon a first portion of a first surface of a substrate; bonding a metalplate on a second surface of the substrate so as to expose a secondportion of the second surface of the substrate opposite to theelectronic element; wherein the second surface is opposite to the firstsurface; and sealing the first surface of the substrate and the secondsurface of the substrate with a resin mold so as to expose the metalplate. The resin mold sandwiches the first portion of the first surfaceand the second portion of the second surface of the substrate.

According to the above method, the structure can prevent a deflectedforce from being applied to the substrate and prevent deformation of thesubstrate and the electronic element.

According to an eleventh aspect of the present disclosure, amanufacturing method of an electronic device includes: forming anelectronic element in a substrate; wherein the substrate includes afirst surface and a second surface opposite to the first surface; andthe first surface includes a first portion corresponding to theelectronic element; bonding a metal plate to the second surface of thesubstrate so as to expose a second portion of the second surface of thesubstrate opposite to the first portion of the first surface; andsealing the first surface of the substrate and the second surface of thesubstrate with a resin mold so as to expose the metal plate. The resinmold sandwiches the first portion of the first surface and the secondportion of the second surface of the substrate.

According to the above method, the structure can prevent a deflectedforce from being applied to the substrate and prevent deformation of thesubstrate and the electronic element.

According to a twelfth aspect of the present disclosure, a manufacturingmethod of an electronic device includes: mounting an electronic elementon a first surface of a ceramic substrate; wherein the ceramic substratehas the first surface and a second surface opposite to the firstsurface; and sealing the first surface of the ceramic substrate and thesecond surface of the ceramic substrate with a resin mold so as toexpose an inner portion of the second surface. The first surface has anouter edge (391 a), and the second surface has an outer edge (392 b),and the resin mold sandwiches the outer edge of the first surface andthe outer edge of the second surface.

According to the structure, it is possible to prevent deformation of theceramic substrate and the electronic element.

According to a thirteenth aspect of the present disclosure, amanufacturing method of an electronic device includes: mounting anelectronic element on an inner portion of a second surface of a ceramicsubstrate; wherein the ceramic substrate has a first surface and thesecond surface opposite to the first surface; sealing the first surfaceof the ceramic substrate and the second surface of the ceramic substratewith a resin mold so as to expose the electronic element and the innerportion of the second surface. The first surface has an outer edge (391a), and the second surface has an outer edge (392 b), and the resin moldsandwiches the outer edge of the first surface and the outer edge of thesecond surface.

The ceramic substrate can be prevented from deformation. Since theelectronic element inappropriate for molding is not sealed with theresin mold, it is possible to prevent the electronic element fromcharacteristic degradation or failure due to a molding pressure of theresin mold.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will become more apparent from the following detaileddescription made with reference to the accompanying drawings. In thedrawings:

FIGS. 1A and 1B show an electronic device according to a firstembodiment, in which FIG. 1A is a schematic sectional view and FIG. 1Bis a schematic plan view viewed from the bottom of FIG. 1A;

FIGS. 2A to 2C are process diagrams showing a manufacturing method ofthe electronic device according to the first embodiment;

FIG. 3 is a schematic sectional view showing an example of mounting theelectronic device according to the first embodiment on a housing;

FIG. 4 is a schematic sectional view showing another example of mountingthe electronic device according to the first embodiment on a housing;

FIG. 5 is a schematic sectional view showing another example of theelectronic device according to the first embodiment;

FIG. 6A is a schematic sectional view showing still another example ofthe electronic device according to the first embodiment, and FIG. 6B isa schematic sectional view showing a bonding surface of the metal platein FIG. 6A;

FIGS. 7A to 7C are process diagrams showing a manufacturing method of anelectronic device according to a second embodiment;

FIGS. 8A and 8B are process diagrams showing a manufacturing method ofan electronic device according to a third embodiment;

FIG. 9 is a schematic sectional view showing a manufacturing method ofan electronic device according to a fourth embodiment;

FIG. 10 is an enlarged view near a second electronic component of theelectronic device in FIG. 9;

FIGS. 11A to 11C are process diagrams showing a manufacturing process ofa ceramic substrate having a depressed portion of the electronic deviceaccording to the fourth embodiment;

FIGS. 12A to 12C are process diagrams showing the manufacturing processof the ceramic substrate continued from FIGS. 11A to 11C;

FIGS. 13A to 13C are schematic sectional views showing examples of anelectronic device according to a fifth embodiment;

FIGS. 14A to 14C are schematic sectional views showing examples of anelectronic device according to a sixth embodiment;

FIG. 15 is a schematic sectional view showing a first example of anelectronic device according to a seventh embodiment;

FIG. 16 is a schematic sectional view showing a second example of theelectronic device according to the seventh embodiment;

FIG. 17 is a schematic sectional view showing a third example of theelectronic device according to the seventh embodiment;

FIGS. 18A and 18B show an electronic device according to an eighthembodiment, in which FIG. 18A is a schematic sectional view and FIG. 18Bis a schematic plan view viewed from the bottom of FIG. 18A;

FIG. 19 is a schematic sectional view showing another example of theelectronic device according to the eighth embodiment;

FIGS. 20A and 20B are schematic sectional views showing still anotherexample of the electronic device according to the eighth embodiment, inwhich FIG. 20A shows an example of wire bonding connection and FIG. 20Bshows an example of tape connection;

FIGS. 21A to 21C are schematic sectional views of an electronic deviceaccording to a ninth embodiment;

FIGS. 22A and 22B show a first example of an electronic device accordingto a tenth embodiment, in which FIG. 22A is a schematic sectional viewand FIG. 22B is a schematic plan view viewed from the bottom of FIG.22A;

FIGS. 23A and 23B show a second example of the electronic deviceaccording to the tenth embodiment, in which FIG. 22A is a schematicsectional view and FIG. 22B is a schematic plan view viewed from thebottom of FIG. 22A;

FIGS. 24A and 24B show a first example of an electronic device accordingto an eleventh embodiment, in which FIG. 24A is a schematic sectionalview and FIG. 24B is a schematic plan view viewed from the bottom ofFIG. 24A;

FIGS. 25A and 25B show a second example of the electronic deviceaccording to the eleventh embodiment, in which FIG. 25A is a schematicsectional view and FIG. 25B is a schematic plan view viewed from thebottom of FIG. 25A;

FIGS. 26A and 26B show an electronic device according to a twelfthembodiment, in which FIG. 26A is a schematic sectional view and FIG. 26Bis a schematic plan view viewed from the bottom of FIG. 26A;

FIGS. 27A and 27B show an electronic device according to a thirteenthembodiment, in which FIG. 27A is a schematic sectional view and FIG. 27Bis a schematic plan view viewed from the bottom of FIG. 27A;

FIGS. 28A and 28B show an electronic device according to a fourteenthembodiment, in which FIG. 28A is a schematic sectional view and FIG. 28Bis a schematic plan view viewed from the bottom of FIG. 28A;

FIGS. 29A to 29C are schematic plan views showing various planar shapesof a molding resin on a second surface of a substrate according to afifteenth embodiment;

FIG. 30 is a schematic sectional view showing an electronic device as aprototype according to a related art;

FIGS. 31A and 31B show an electronic device according to a sixteenthembodiment, in which FIG. 31A is a sectional view and FIG. 31B is aschematic plan view of the electronic device viewed from the bottom ofFIG. 31A;

FIG. 32 shows a manufacturing process of the electronic device shown inFIGS. 31A and 31B;

FIG. 33 is a schematic plan view of the electronic device according to aseventeenth embodiment viewed from the bottom of the electronic device;

FIG. 34 is a schematic plan view of the electronic device according toan eighteenth embodiment viewed from the bottom of the electronicdevice;

FIGS. 35A and 35B show an electronic device according to a nineteenthembodiment, in which FIG. 35A is a sectional view and FIG. 35B is aschematic plan view of the electronic device viewed from the bottom ofFIG. 35A;

FIG. 36 is a schematic plan view of the electronic device according to atwentieth embodiment;

FIG. 37 is a schematic plan view of the electronic device according to atwenty-first embodiment;

FIG. 38 is a schematic plan view of the electronic device according to atwenty-second embodiment;

FIG. 39 is a schematic plan view of the electronic device according to atwenty-third embodiment;

FIG. 40 is a schematic plan view of the electronic device according to atwenty-fourth embodiment;

FIG. 41 is a schematic plan view of the electronic device according to atwenty-fifth embodiment; and

FIG. 42 is a schematic plan view of the electronic device according to atwenty-sixth embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

FIGS. 1A and 1B show an electronic device 100 according to a firstembodiment, in which FIG. 1A is a schematic sectional view and FIG. 1Bis a schematic plan view viewed from the bottom of FIG. 1A.

The electronic device 100 according to the embodiment mainly includes aceramic substrate 10, a first electronic component 20, a secondelectronic component 30, a metal plate 50, a lead frame 70, and amolding resin 80. The first electronic component 20 is mounted on afirst surface of the ceramic substrate 10. The second electroniccomponent 30 is mounted on a second surface of the ceramic substrate 10.The metal plate 50 is bonded to the second surface of the ceramicsubstrate 10 through an adhesive 40. The lead frame 70 is connected tothe ceramic substrate 10 through a wire 60. The molding resin 80 sealsthe components 10 through 70.

As shown in FIGS. 1A and 1B, the electronic device 100 is a squareplate-shaped mold package. For example, the package size isapproximately 50×50×6.6 mm depending on mounted electronic components, acircuit scale, or types of the electronic components.

The ceramic substrate 10 is a single-layer or multilayer substrate madeof ceramics such as alumina and is configured as a wiring substratehaving a wiring (not shown). The ceramic substrate 10 is shaped into asquare plate in plan view. A first surface of the ceramic substrate 10corresponds to a first surface of the substrate 10 and a second surfacethereof corresponds to a second surface of the substrate 10.

Preferably, the ceramic substrate 10 is an alumina laminate substrateindicating linear expansion coefficient a1 between 5 and 8 ppm/° C. Theceramic substrate 10 is preferably sized 40 by 40 mm or smaller and is0.8 mm thick or more.

The first electronic component 20 is mounted on a first surface (uppersurface in FIG. 1A) of the ceramic substrate 10. The first electroniccomponent 20 is electrically connected to the ceramic substrate 10 via abonding wire such as Al or Au or a die mount material such as solder orelectrically conductive adhesive. The first electronic component 20includes components such as a coil, power device, control device,capacitor, and oscillator.

The second electronic component 30 is mounted on a second surface (lowersurface in FIG. 1A) opposite to the first surface and represents acontrol device or a resistor, for example. In FIGS. 1A and 1B, thesecond electronic component 30 is a flip chip as a control device and iselectrically connected to the substrate 10 via a bump 31. An underfill32 of epoxy resin, for example, is filled between the second electroniccomponent 30 and the substrate 10.

The adhesive 40 is used to bond the metal plate 50 to a portion of thesecond surface of the ceramic substrate 10 except a portion for mountingthe second electronic component 30. According to the embodiment, themetal plate 50 is made by processing the same plate material as the leadframe 70, that is, a lead frame material, and is configured as an islandfor the lead frame material. In this embodiment, the thickness of themetal plate 50 is equivalent to that of the lead frame 70.

A Cu lead frame material is widely used for the metal plate 50 and thelead frame 70 in consideration for radiation performance. However, theCu material causes a large difference in linear expansion coefficientsfrom the ceramic substrate 10. A Fe material may be used for the purposeof consistency in the linear expansion coefficients.

Specifically, a preferable lead frame material indicates linearexpansion coefficient a of smaller than or equal to 11 and Young'smodulus E of smaller than 200 GPa in consideration for consistency ofthe linear expansion coefficient with the substrate 10 and a stress atthe substrate edge. More preferably, the lead frame material may beconditioned to be a <9 GPa and E<150 GPa. In consideration forweldability, the lead frame material may be plated with PPF (Ni/Pd/Au)such as electrolytic nickel, Sn, and Au. The material surface may beroughened to prevent the molding resin 80 from peeling off.

The metal plate 50 is positioned correspondingly to a heater elementsuch as a power element belonging to the first electronic component 20mounted on the first surface 311 of the ceramic substrate 10. The heaterelement is connected to the first surface of the ceramic substrate 10via Ag paste. For reliable heat transfer, the Ag paste preferablyindicates a thermal conductivity of greater than or equal to 4 W/m·K.

According to the embodiment, a resistor 90 is provided at a portion ofthe second surface of the ceramic substrate corresponding to the metalplate 50. The metal plate 50 is provided via the adhesive 40 so as tocover the resistor 90.

The adhesive 40 for bonding the metal plate 50 uses silicone resin as amain component, for example. The adhesive 40 preferably indicates 4w/m·Kor more so as to transfer heat on the ceramic substrate 10. The adhesive40 is also used to seal the resistor 90. The adhesive 40 preferablyindicates Young's modulus E of smaller than 8 GPa to protect theresistor 90.

The wire 60 is provided as an Au or Al bonding wire and is formed byordinary wire bonding. The molding resin 80 uses a mold material made ofepoxy resin generally used for the field of such electronic devices.Transfer mold technique is used to form the molding resin 80.

The molding resin 80 often uses a resin with heat expansion coefficienta ranging between 8 and 14 for consistency of heat expansion coefficienta between each member and the ceramic substrate 10. The resin needs tofeature a long gel time and low viscosity in consideration for fillingefficiency of the molding resin 80 on the second surface of the ceramicsubstrate 10. The molding resin 80 preferably indicates a high glasstransition point Tg for use under a high temperature.

The following shows a preferred example of the molding resin 80. For usewith the metal plate 50 and the lead frame 70 made of Cu, the moldingresin 80 preferably indicates such properties as linear expansioncoefficient a1<17, Young's modulus E1<20 GPa, minimum melt viscosity <30Pa·s (175° C.), gel time >20 seconds, and spiral flow >80 cm. Themolding resin 80 preferably indicates Tg<150° C. or more preferablyTg<175° C. Further, the molding resin 80 preferably indicates 10<a1<14,E1<17 GPa, and the minimum melt viscosity of 20 (Pa·s) or less.Moreover, the molding resin 80 preferably indicates the gel time ofshorter than 25 seconds and the spiral flow of 100 cm.

The lead frame 70 is partially protrudes as an outer lead from themolding resin 80. The outer leads enable electric connection between theelectronic device 100 and the outside.

According to the electronic device 100, the molding resin 80 seals thesecond electronic component 30 on the second surface of the ceramicsubstrate 10. The surface opposite to the bonding surface of the metalplate 50 is exposed from the molding resin 80. As shown in FIG. 1A, themolding resin 80 for sealing the second electronic component 30protrudes outward (downward in FIG. 1A) from the surface exposed fromthe molding resin 80 for the metal plate 50.

As shown in FIG. 1B, the metal plate 50 is not provided for a portion ofthe second surface of the ceramic substrate 10 corresponding to thesecond electronic component 30. The metal plate 50 is provided for aportion of the second surface of the ceramic substrate 10 outside thesecond electronic component 30 so as to avoid the second electroniccomponent 30.

According to the example in FIG. 1B, the metal plate 50 is divided intofour portions. Each metal plate 50 is arranged around the secondelectronic component 30. According to this arrangement, the moldingresin 80 for sealing the second electronic component 30 is exposed fromthe metal plate 50 on the second electronic component 30.

The following describes a manufacturing method of the electronic device100 according to the embodiment with reference to FIGS. 2A to 2C. FIGS.2A to 2C are process diagrams showing the manufacturing method andprovides sectional views of a work corresponding to processes.

As shown in FIG. 2A, the first electronic component 20 and the secondelectronic component 30 are mounted on the first and second surfaces ofthe ceramic substrate 10, respectively. Wire bonding is conducted asnecessary. The wire bonding is used to connect the ceramic substrate 10with the lead frame 70 through the wire 60.

As shown in FIG. 2B, the adhesive 40 is used to bond the metal plate 50to a portion of the second surface of the ceramic substrate 10 otherthan the second electronic component 30. As shown in FIG. 2C, themolding resin 80 is used to seal the work.

In this mold process, the work as shown in FIG. 2B is placed on a die(not shown). The molding resin 80 is injected into the die. The surfaceopposite to the bonding surface of the metal plate 50 is closelyattached to the die so as not to be sealed by the molding resin 80.

In the mold process, the molding resin 80 is used to seal the ceramicsubstrate 10, the first electronic component 20, and the secondelectronic component 30 at a time. Specifically, the molding resin 80injected into the die flows over the first and second surfaces of theceramic substrate 10. Accordingly, both the electronic components 20 and30 are molded simultaneously (see FIG. 2C). Completing the sealingcompletes the electronic device 100 according to the embodiment as shownin FIGS. 1A and 1B.

According to the embodiment, the first electronic component 20 ismounted on the first surface of the ceramic substrate. The secondelectronic component 30 is mounted on the second surface thereof. Thefirst electronic component 20 and the second electronic component 30 areboth sealed with the molding resin 80.

In the mold process, the molding resin 80 seals the first and secondelectronic components 20 and 30 simultaneously. The molding resin 80 isinjected to both the first and second surfaces of the ceramic substrate10.

The embodiment decreases a stress of the molding resin 80 on the ceramicsubstrate 10 from the first surface of the same in comparison with aconventional technique that provides sealing by applying an adhesivesofter than a molding resin to the second surface of a ceramicsubstrate. As a result, the embodiment can prevent the ceramic substrate10 from cracking during the mold process.

According to the embodiment, the adhesive 40 is used to bond the metalplate 50 to a portion other than the portion of the second surface ofthe ceramic substrate 10 corresponding to the second electroniccomponent 30. The surface opposite to the bonding surface of the metalplate 50 is exposed from the molding resin 80. This makes it possible toappropriately ensure a heat dissipation function of the metal plate 50.

FIG. 3 is a schematic sectional view showing an example of mounting theelectronic device 100 according to the first embodiment on a housing200. The housing 200 represents a metal container or plate. A bondingmember 201 is used to bond the electronic device 100 to the housing 200on the surface of the metal plate 50 exposed from the molding resin 80.The bonding member 201 represents solder or electrically conductiveadhesive excellent in heat conductivity.

Contact efficiency of the bonding member 201 may be improved by weldingthe electronic device 100 and the housing 200, pressing both using aspringy member, or screwing both.

FIG. 4 is a schematic sectional view showing another example of mountingthe electronic device 100 according to the first embodiment on thehousing 200. When a gel excellent in heat conductivity is used as thebonding member 201, for example, it may be preferable to provide asealing member 202 such as an O ring for sealing the bonding member 201.In this case, the electronic device 100 may be mounted on the housing200 by providing the bonding member 201 between the electronic device100 and the housing 200 and providing the sealing member 202 around thebonding member 201.

FIG. 5 is a schematic sectional view showing another example of theelectronic device 100 according to the first embodiment. In the exampleof FIGS. 1A and 1B, the metal plate 50 and the lead frame 70 are formedby using the same plate material with the same thickness. In the exampleof FIG. 5, the metal plate 50 may use a plate material such as a heatthink different from the lead frame 70 and may be thicker than the leadframe 70.

FIG. 6A is a schematic sectional view showing still another example ofthe electronic device 100 according to the first embodiment. FIG. 6B isa schematic sectional view showing bonding surface of the metal plate 50for the electronic device 100 in FIG. 6A.

In the example of FIGS. 1A and 1B, the metal plate 50 is provided at theportion of the second surface of the ceramic substrate 10 so as to avoidthe second electronic component 30. In the example of FIG. 6, the metalplate 50 covers the second electronic component 30 via the molding resin80 on the second surface of the ceramic substrate 10.

A groove 51 is provided on the surface of the metal plate 50 forcovering the second electronic component 30 in order to ensure theheight of the second electronic component 30. The groove 51 is formedacross one end to the other of the metal plate 50 in order to seal thesecond electronic component 30 with the molding resin 80 in the moldprocess. The molding resin 80 injected into the die during the moldprocess flows in the groove 51 and seals the second electronic component30.

Second Embodiment

FIGS. 7A to 7C are process diagrams showing a manufacturing method of anelectronic device according to the second embodiment and providessectional views of a work corresponding to processes. The manufacturingmethod is used to finally manufacture the electronic device as shown inFIG. 7C. The following mainly describes differences from themanufacturing method according to the first embodiment.

As shown in FIG. 7A, the first electronic component 20 and the secondelectronic component 30 are mounted on the first and second surfaces ofthe ceramic substrate 10, respectively. The wire 60 is used to connectthe ceramic substrate 10 with the lead frame 70.

According to the embodiment, as shown in FIG. 7B, a second electroniccomponent sealing resin 81 is used to seal the second electroniccomponent 30 on the second surface of the ceramic substrate 10. Thesecond electronic component sealing resin 81 indicates Young's modulusof 100 MPa or more at a molding temperature of the molding resin 80 forsealing. The second electronic component sealing resin 81 is harder thana conventional adhesive made of silicone resin for bonding metal platesand ceramic substrates.

The second electronic component sealing resin 81 may or may not beequivalent to the molding resin 80. Preferably, the second electroniccomponent sealing resin 81 is as hard as or harder than the moldingresin 80 and may represent epoxy resin.

The above-mentioned molding temperature of the molding resin 80 forsealing refers to the temperature of the melted molding resin 80 to beinjected into the die during the mold process. For example, the moldingresin 80 made of general epoxy resin indicates the molding temperatureof 175° C.

According to the embodiment, as shown in FIG. 7B, the second electroniccomponent sealing resin 81 is used for sealing. The adhesive 40 is usedto bond the metal plate 50 to the portion of the second surface of theceramic substrate 10 other than the second electronic component 30. Thework is sealed with the molding resin 80.

In this mold process, the work as shown in FIG. 7B is placed on a die(not shown). The molding resin 80 is injected into the die. Also in thisprocess, the surface opposite to the bonding surface of the metal plate50 and the second electronic component sealing resin 81 are closelyattached to the die so as not to be sealed by the molding resin 80.

In the mold process, the molding resin 80 is used to seal the ceramicsubstrate 10 and the first electronic component 20. Completing thesealing completes the electronic device according to the embodiment asshown in FIG. 7C.

Before sealing using the molding resin 80 according to the embodiment,the second electronic component 30 is mounted on the second surface ofthe ceramic substrate 10. The second electronic component sealing resin81 is used to seal the second electronic component 30.

When the molding resin 80 is used to seal the first electronic component20, the second electronic component sealing resin 81 harder than theabove-mentioned conventional adhesive is provided at the portion of thesecond surface of the ceramic substrate 10 corresponding to the secondelectronic component 30. The resin 81 supports the ceramic substrate 10.The embodiment decreases a stress on the ceramic substrate 10 from thefirst surface of the same. As a result, the embodiment can prevent theceramic substrate 10 from cracking during the mold process.

Also according to the embodiment, the adhesive 40 is used to bond themetal plate 50 to a portion other than the portion of the second surfaceof the ceramic substrate 10 corresponding to the second electroniccomponent 30. The surface opposite to the bonding surface of the metalplate 50 is exposed from the molding resin 80. This makes it possible toappropriately ensure a heat dissipation function of the metal plate 50.

Third Embodiment

FIGS. 8A and 8B are process diagrams showing a manufacturing method ofan electronic device according to a third embodiment and providessectional views of a work corresponding to processes. The manufacturingmethod is used to finally manufacture the electronic device as shown inFIG. 8B. The following mainly describes differences from themanufacturing method according to the first embodiment.

The first electronic component 20 and the second electronic component 30are mounted on the first and second surfaces of the ceramic substrate10, respectively. The wire 60 is used to connect the ceramic substrate10 with the lead frame 70. The adhesive 40 is used to bond the metalplate 50 to the portion of the second surface of the ceramic substrate10 other than the second electronic component 30.

The embodiment uses the molding resin 80 to seal the work as shown inFIG. 8A. During the mold process based on the transfer mold method, themolding resin 80 is used to seal the whole of the second electroniccomponent 30 and the metal plate 50 as well as the ceramic substrate 10and the first electronic component 20.

As shown in FIG. 8B, a technique of cutting, grinding, or sandblastingis used to remove the portion of the molding resin 80 for sealing thesurface opposite to the bonding surface of the metal plate 50. As aresult, the surface opposite to the bonding surface of the metal plate50 is exposed from the molding resin 80 to complete the electronicdevice according to the embodiment as shown in FIG. 8B.

According to the embodiment, the molding resin 80 is used to seal thewhole of the ceramic substrate 10 during the mold process. The moldingresin 80 is injected to both the first and second surfaces of theceramic substrate 10. The embodiment decreases a stress of the moldingresin 80 on the ceramic substrate 10 from the first surface of the same.As a result, the embodiment can prevent the ceramic substrate 10 fromcracking during the mold process.

Fourth Embodiment

FIG. 9 is a schematic sectional view showing a manufacturing method ofthe electronic device 110 according to the fourth embodiment. FIG. 10 isan enlarged view near the second electronic component 30 of theelectronic device 110 in FIG. 9. The electronic device 110 according tothe embodiment is provided by partially modifying the electronic deviceaccording to the first embodiment. The following mainly describesdifferences from the first embodiment.

As shown in FIG. 9, the electronic device 110 according to theembodiment includes a depressed portion 10 a. The depressed portion 10 ais formed on the second surface of the ceramic substrate 10 so as toposition the second electronic component 30 on the second surface of theceramic substrate 10. The second electronic component 30 is mounted atthe bottom of the depressed portion 10 a.

The molding resin 80 is also used to seal the second electroniccomponent 30 of the electronic device 110. Instead of the molding resin80, the second electronic component sealing resin 81 may be used to sealthe second electronic component 30.

The embodiment can provide the same effect as the first embodiment anddecrease the protrusion of the second electronic component 30 on thesecond surface of the ceramic substrate 10. The embodiment can minimizethe size of the electronic device 110 along the thickness direction ofthe ceramic substrate 10.

As seen from the electronic device according to the first embodiment(see FIGS. 1A and 1B), the molding resin 80 for sealing the secondelectronic component 30 protrudes from the surface of the metal plate 50exposed from the molding resin 80. The fourth embodiment not onlydecreases the amount of protrusion but also retracts the secondelectronic component 30 from the exposed surface of the metal plate 50to level the molding resin 80 for sealing the second electroniccomponent 30 with the exposed surface of the metal plate 50.

According to the embodiment as shown in FIGS. 9 and 10, the ceramicsubstrate 10 is configured to be multilayer having ceramic layers 11through 14. Of the four ceramic layers 11 through 14, the ceramic layer11 forms the second surface of the ceramic substrate 10. According tothe embodiment, the depressed portion 10 a is formed by making a hole inthe ceramic layer 11.

The following shows examples of dimensions t1 through t6 in FIG. 10. Inthis example, thickness t1 of the ceramic substrate 10 is 0.8 mmequivalent to the four ceramic layers 11 through 14 each of which is 0.2mm thick. Therefore, depth t2 of the depressed portion 10 a is 0.2 mm.Thickness t3 of the adhesive 40 is 0.15 mm. Thickness t4 of the metalplate 50 is 0.25 mm. Thickness t5 of the second electronic component 30is 0.4 mm. Height t6 of the bump 31 is 0.08 mm.

With reference to FIGS. 11A to 11C and 12A to 12C, the followingdescribes the manufacturing method of the electronic device 110 shown inFIG. 9 according to the embodiment. FIGS. 11A to 11C and 12A to 12C areprocess diagrams showing an example process of fabricating the ceramicsubstrate 10 having the depressed portion 10 a in the electronic device110.

As shown in FIG. 11A, the ceramic layers 11 through 14 are prepared as agreen sheet made of alumina. A drilling process such as punching isconducted to form a hole 10 b as a via hole and the hole for thedepressed portion 10 a in the ceramic layers 11 through 14.

As shown in FIG. 11B, the hole 10 b as a via hole is filled with anelectrically conductive paste 10 c that is then dried. The electricallyconductive paste 10 c is a mixture of molybdenum and alumina, forexample. As shown in FIG. 11C, necessary portions on the surfaces of theceramic layers 11 through 14 are printed with an electrically conductivepaste 10 d that is then dried. The electrically conductive paste 10 d ismade of tungsten, for example.

As shown in FIG. 12A, the ceramic layers 12 through 14 are layeredexcept the ceramic layer 11 having the depressed portion 10 a and aresandwiched between a die K1 to be unified. As shown in FIGS. 12B and12C, the ceramic layer 11 having the depressed portion 10 a is alsolayered to be unified.

The bottom part of a die K2 may be flat or shaped in accordance with thedepressed portion 10 a as shown in FIG. 12B in order to apply moreuniform pressure. A layered product of the ceramic layers 11 through 14is then burnt in the reduction atmosphere of 1600° C. The layeredproduct is burnt to shrink approximately 18% as a whole.

Though the subsequent processes are not shown, nonelectrolytic platingusing Cu or Au is applied to a conductive portion of the surface of theceramic substrate 10. The resistor 90 is formed on the second surface ofthe ceramic substrate 10 by printing and burning. The resistor 90 iscovered with protective glass or resin. Finally, the ceramic substrate10 having the depressed portion 10 a is completed.

The second electronic component 30 is mounted on the depressed portion10 a of the second surface of the ceramic substrate 10 via the bump 31made of solder. The underfill 32 is filled between the second electroniccomponent 30 and the ceramic substrate 10.

The metal plate 50 is bonded to the second surface of the ceramicsubstrate 10 via the adhesive 40 made of silicone rubber, for example.The first electronic component 20 is mounted on the first surface of theceramic substrate 10. As shown in FIG. 9, wire bonding is conductedbetween the ceramic substrate 10 and the lead frame 70 to connect bothusing the wire 60.

Similarly to the first embodiment, the molding resin 80 is then used toseal the second electronic component 30 as well as the ceramic substrate10 and the first electronic component 20 at a time. Completing thesealing completes the electronic device 110 according to the embodimentas shown in FIG. 9.

The mold process of this embodiment may be equal to that of the thirdembodiment. In this case, the same method may be used except the use ofthe ceramic substrate 10 having the depressed portion 10 a.

As mentioned above, the second electronic component sealing resin 81 maybe used to seal the second electronic component 30 of the electronicdevice 110. The manufacturing method described in the second embodimentmay be used to fabricate the electronic device 110 according to thefourth embodiment. That is, the fourth embodiment can be combined withthe other embodiments mentioned above.

In the example of FIG. 9, the embodiment uses the multilayer ceramicsubstrate 10 to form the depressed portion 10 a. The ceramic substrate10 may be single-layer when applicable.

Fifth Embodiment

FIGS. 13A to 13C are schematic sectional views showing examples of anelectronic device according to the fifth embodiment. FIGS. 13A, 13B, and13C show first, second, and third examples of the embodiment,respectively.

As shown in FIG. 10, the fourth embodiment configures the depressedportion 10 a on the second surface of the ceramic substrate 10 by holingthe single ceramic layer 11 that forms the second surface of the ceramicsubstrate 10. In addition, the depressed portion 10 a may be configuredby holing the two ceramic layers 11 and 12 as shown in FIG. 13A. Thedepressed portion 10 a may be configured by holing the three ceramiclayers 11 through 13 as shown in FIG. 13B.

FIG. 13C shows a configuration of mounting the second electroniccomponent 30 on the depressed portion 10 a. Similarly to FIG. 6, themetal plate 50 may cover the second electronic component 30 via themolding resin 80.

Instead of the molding resin 80, the second electronic component sealingresin 81 or the underfill 32 may be used to seal the second electroniccomponent 30. In this case, the metal plate 50 may be bonded after thesecond electronic component 30 is sealed with the second electroniccomponent sealing resin 81 or the underfill 32.

Sixth Embodiment

FIGS. 14A to 14C are schematic sectional views showing examples of anelectronic device according to the sixth embodiment. FIGS. 14A, 14B, and14C show first, second, and third examples of the embodiment,respectively.

The fourth and fifth embodiments use a flip chip for the secondelectronic component 30 mounted at the depressed portion 10 a on thesecond surface of the ceramic substrate 10. The second electroniccomponent 30 may be a semiconductor device mounted through the use of awire 33 such as gold according to the sixth embodiment.

The side of the depressed portion 10 a is not limited to be straight andmay be tapered as shown in FIG. 14B or stepped as shown in FIG. 14C. Theshape of the depressed portion 10 a can be easily changed by means ofthe above-mentioned drilling process such as punching.

Seventh Embodiment

FIGS. 15, 16, and 17 are schematic sectional views showing first,second, and third examples of an electronic device according to theseventh embodiment, respectively. The single second electronic component30 is mounted on the second surface of the ceramic substrate 10according to the above-mentioned embodiments. Further, multiple secondelectronic components 30 may be mounted.

FIGS. 15 to 17 show examples of mounting the second electronic component30 on the depressed portion 10 a. FIGS. 15 to 17 omit the molding resin80 for sealing the second electronic component 30 and the secondelectronic component sealing resin 81. The examples use a flip chip anda capacitor as the second electronic component 30.

As shown in FIG. 15, the single depressed portion 10 a may be mountedwith multiple second electronic components 30. As shown in FIG. 16, thesingle depressed portion 10 a may be provided for one of secondelectronic components 30. As shown in FIG. 17, the multiple depressedportions 10 a may have different depths.

Eighth Embodiment

FIGS. 18A and 18B show an electronic device according to the eighthembodiment. FIG. 18A is a schematic sectional view. FIG. 18B is aschematic plan view viewed from the bottom of FIG. 18A. The embodimentmainly describes differences from the electronic device 100 (see FIGS.1A and 1B) according to the first embodiment.

The electronic device according to the embodiment mainly includes theceramic substrate 10, the first electronic component 20, the secondelectronic component 30, the lead frame 70, and the molding resin 80.The first electronic component 20 is mounted on the first surface of theceramic substrate 10. The second electronic component 30 is mounted onthe second surface of the ceramic substrate 10. The lead frame 70 isconnected to the ceramic substrate 10 through the wire 60. The moldingresin 80 seals the components 10 through 70.

The electronic device according to the embodiment is configured byomitting the metal plate from the first embodiment. The eighthembodiment exposes a portion other than the portion of the secondsurface of the ceramic substrate 10 corresponding to the secondelectronic component 30 from the molding resin 80. That exposed portionof the second surface of the ceramic substrate 10 is therefore void ofthe molding resin 80 and is provided as an opening 80 a.

The following describes a manufacturing method of the electronic deviceaccording to the embodiment. Similarly to the first embodiment, thefirst electronic component 20 and the second electronic component 30 aremounted on the first and second surfaces of the ceramic substrate 10,respectively. The wire 60 is used to connect the ceramic substrate 10with the lead frame 70 according to the wire bonding.

The work is placed on a die (not shown) and is sealed with the moldingresin 80. The portion of the second surface of the ceramic substrate 10other than the portion corresponding to the second electronic component30 is closely attached to the die so as not to be sealed by the moldingresin 80.

In the mold process, similarly to the first embodiment, the moldingresin 80 is used to seal the ceramic substrate 10, the first electroniccomponent 20, and the second electronic component 30 at a time. Themolding resin 80 injected into the die flows over the first and secondsurfaces of the ceramic substrate 10. Accordingly, both the electroniccomponents 20 and 30 are molded simultaneously. Completing the sealingwith the molding resin 80 completes the electronic device according tothe embodiment.

According to the embodiment, the first electronic component 20 is alsomounted on the first surface of the ceramic substrate. The secondelectronic component 30 is mounted on the second surface thereof. Thefirst electronic component 20 and the second electronic component 30 areboth sealed with the molding resin 80. In the mold process, the moldingresin 80 is injected to both the first and second surfaces of theceramic substrate 10.

The embodiment also decreases a stress of the molding resin 80 on theceramic substrate 10 from the first surface of the same in the moldprocess. As a result, the embodiment can prevent the ceramic substrate10 from cracking in the mold process.

In the electronic device according to this embodiment and the firstembodiment, the substrate 10 is not limited to a ceramic substrate andmay represent a printed substrate made of resin or a metal substrate.

FIG. 19 is a schematic sectional view showing another example of theelectronic device according to the eighth embodiment. This example usesa printed substrate for the substrate 10. A thermal via hole 15 isprovided for the portion of the second surface of the substrate 10exposed from the opening 80 a of the molding resin 80. The exposedportion is provided so as to avoid the other portion corresponding tothe second electronic component 30.

The thermal via hole 15 is formed through the first and second surfaceof the substrate 10 and is filled with metal paste such as Cu by meansof printing or plating. The thermal via hole 15 is used for heatdissipation of the substrate 10. In this example, the thermal via hole15 is exposed from the molding resin 80 to improve the radiationperformance of the substrate 10 through the thermal via hole 15.

FIGS. 20A and 20B are schematic sectional views showing still anotherexample of the electronic device according to the eighth embodiment.FIG. 20A shows an example of wire bonding connection for the secondelectronic component 30. FIG. 20B shows an example of tape connectionfor the same. According to the embodiment, the wire 33 made of gold oraluminum or a tape member 34 such as a flexible printed substrate orribbon-shaped wiring may be used for connection with the secondelectronic component 30.

The electronic device according to the embodiment is configured byexcluding the metal plate from the electronic device according to thefirst embodiment. The electronic device according to the eighthembodiment may be fabricated by the same procedure as the second orthird embodiment. The eighth embodiment may use the ceramic substrate 10having the depressed portion 10 a as described in the fourth embodimentor may be combined with the other embodiments mentioned above.

According to the embodiment, the adhesive 40 may be used to bond themetal plate 50 to the portion of the substrate 10 exposed from themolding resin 80 other than the portion corresponding to the secondelectronic component 30. The surface opposite to the bonding surface ofthe metal plate 50 may be exposed from the molding resin 80. Thisconfiguration is the same as that of the electronic device according tothe first embodiment.

Ninth Embodiment

FIGS. 21A to 21C are schematic sectional views of an electronic deviceaccording to the ninth embodiment. FIGS. 21A, 21B, and 21C show first,second, and third examples of the embodiment, respectively. Theseexamples attach additional components 35 through 39 to the electronicdevices described in the first through seventh embodiments on surfacesof the metal plate 50 exposed from the molding resin 80.

FIG. 21A shows a sensor device 35 such as a pressure sensor, anglesensor, or temperature sensor and a passive device 36 mounted onsurfaces of the metal plate 50 exposed from the molding resin 80. Thedevices may be bonded. A protective plate 37 such as a glass plate isbonded to seal the components 35 and 36. According to this example, theelectronic device is preferably used as a sensor assembly.

FIG. 21B shows a heat dissipation fin 38 made of aluminum or copperattached to the surface of the metal plate 50 exposed from the moldingresin 80 so as to improve the radiation performance. The heatdissipation fin 38 contacts with the metal plate 50 via heat dissipationgrease (not shown).

FIG. 21C shows a heat dissipation block 39 attached to the surface ofthe molding resin on the first and second surfaces of the substrate 10of the electronic device. The heat dissipation block 39 is made ofaluminum or copper and is fixed by means of bonding or caulking. In thiscase, the electronic device is sandwiched between inner flat opposingsurfaces of both heat dissipation blocks 39 so as to prevent theelectronic device from warping.

The heat dissipation block 39 near the metal plate 50 is thermallyconnected with the metal plate 50 to improve the radiation performance.A spring member 39 a is fixed between the metal plate 50 and the heatdissipation block 39 for the thermal connection. Instead of the springmember 39 a, it may be preferable to use gel such as silicon gelfeaturing the radiation performance.

It is to be distinctly understood that the electronic device accordingto the embodiment may be combined with the manufacturing methods andconfigurations of the above-mentioned embodiments.

Tenth Embodiment

The tenth embodiment describes various examples of arranging the secondelectronic component 30 on the second surface of the substrate 10.

FIGS. 22A and 22B show a first example of an electronic device accordingto a tenth embodiment. FIG. 22A is a schematic sectional view. FIG. 22Bis a schematic plan view viewed from the bottom of FIG. 22A. FIGS. 23Aand 23B show a second example of the electronic device according to thetenth embodiment. FIG. 23A is a schematic sectional view. FIG. 23B is aschematic plan view viewed from the bottom of FIG. 23A.

The first example of the embodiment in FIGS. 22A and 22B shows thesecond electronic component 30 arranged at the center of the secondsurface of the substrate 10. The metal plate 50 is bonded to a peripheryof the second surface of the substrate 10. The metal plate 50 is exposedfrom the molding resin 80.

The second example of the embodiment in FIGS. 23A and 23B shows thesecond electronic component 30 arranged at the periphery of the secondsurface of the substrate 10. The metal plate 50 is bonded to the centerof the second surface of the substrate 10. The metal plate 50 is exposedfrom the molding resin 80.

According to both examples of the embodiment as shown in FIGS. 22A and22B and 23A and 23B, the surface of the molding resin 80 is level withthe surface of the metal plate 50 exposed from the molding resin 80 overthe second surface of the substrate 10. This is advantageous for thefollowing reason. An external heat dissipation member more easilycontacts with the surface of the metal plate 50 than the case ofprotruding the surface of the molding resin 80 from the surface of themetal plate 50 (e.g., see FIGS. 1A and 1B).

Eleventh Embodiment

The eleventh embodiment describes various heat dissipation modes for thesurface of the metal plate 50 exposed from the molding resin 80 over thesecond surface of the substrate 10. Heat dissipation modes are availableto the surface of the metal plate 50 by exchanging heat with heatdissipation members such as solid for solid heat dissipation, gas forgas heat dissipation, and liquid for liquid heat dissipation.

FIGS. 24A and 24B show a first example of an electronic device accordingto the eleventh embodiment. FIG. 24A is a schematic sectional view. FIG.24B is a schematic plan view viewed from the bottom of FIG. 24A. FIGS.25A and 25B show a second example of the electronic device according tothe eleventh embodiment. FIG. 25A is a schematic sectional view. FIG.25B is a schematic plan view viewed from the bottom of FIG. 25A.

The first example of the embodiment in FIGS. 24A and 24B directlycontacts the heat dissipation block 39 with the surface of the metalplate 50 exposed from the molding resin 80 over the second surface ofthe substrate 10 so as to thermally connect the metal plate 50 with theheat dissipation block. Since the exposed surface of the metal plate 50retracts from the molding resin 80, the heat dissipation block 39 isprovided with a protrusion to directly contact with the metal plate 50.

The second example of the embodiment in FIGS. 25A and 25B provides aliquid channel 82 for the surface of the metal plate 50 exposed from themolding resin 80 over the second surface of the substrate 10. The liquidchannel 82 is used for liquid refrigerant such as water and oil to flow.The liquid channel 82 is formed by wall surfaces of the molding resin 80protruding from the exposed surface of the metal plate 50.

It is to be distinctly understood that the embodiment may be combinedwith the manufacturing methods and configurations of the above-mentionedembodiments. For example, the eleventh embodiment may omit the metalplate 50 and directly expose the second surface of the substrate 10 fromthe molding resin 80. The heat dissipation modes in FIGS. 24A and 24Band FIGS. 25A and 25B may be applied to this exposed surface.

Twelfth Embodiment

FIGS. 26A and 26B show an electronic device according to the twelfthembodiment. FIG. 26A is a schematic sectional view. FIG. 26B is aschematic plan view viewed from the bottom of FIG. 26A.

Similarly to the first embodiment or elsewhere, the twelfth embodimentuses the adhesive 40 to bond the metal plate 50 to a portion of thesecond surface of the substrate 10 so as to avoid the portioncorresponding to the second electronic component 30. The surfaceopposite to the bonding surface of the metal plate 50 is exposed fromthe molding resin 80. According to this configuration, the surface ofthe molding resin 80 protrudes outward from the surface of the metalplate 50 exposed from the molding resin 80 over the second surface ofthe substrate 10.

In the configuration of the embodiment as shown in FIGS. 26A and 26B,the molding resin 80 seals the surface of the metal plate 50 along itsperiphery, that is, adjacent to the surface thereof exposed from themolding resin 80.

In FIGS. 1A and 1B or elsewhere, for example, the periphery of thesurface of the metal plate 50 is not sealed with part of the moldingresin 80 adjacent to the surface of the metal plate 50 exposed from themolding resin 80 over the second surface of the substrate 10. Themolding resin 80 ends at the edge of the metal plate 50.

In this case, the line showing the opening of the molding resin 80coincides with the outline of the metal plate 50 when viewed from thesecond surface of the substrate 10. According to the twelfth embodiment,however, the line showing the opening of the molding resin 80 ispositioned inside the outline of the metal plate 50 when viewed from thesecond surface of the substrate 10.

The embodiment can decrease a stress on an interface between the metalplate 50 and the molding resin 80 because the molding resin 80 seals theperiphery of the surface of the metal plate 50. As a result, it ispossible to more improve an effect of preventing the molding resin 80from peeling off the metal plate 50.

It is to be distinctly understood that the embodiment may be alsocombined with the manufacturing methods and configurations of theabove-mentioned embodiments. The embodiment may also omit the metalplate 50 and directly expose the second surface of the substrate 10 fromthe molding resin 80.

Thirteenth Embodiment

FIGS. 27A and 27B show an electronic device according to the thirteenthembodiment. FIG. 27A is a schematic sectional view. FIG. 27B is aschematic plan view viewed from the bottom of FIG. 27A. The thirteenthembodiment is an improvement of the twelfth embodiment.

As shown in FIGS. 27A and 27B, the molding resin 80 seals the surface ofthe metal plate 50 along its periphery, that is, adjacent to the surfacethereof exposed from the molding resin 80 over the second surface of thesubstrate 10. In addition, the embodiment forms a groove 52 in theportion of the molding resin 80 that seals the periphery of the surfaceof the metal plate 50. The groove 52 provides an indentation thatprevents the molding resin 80 from peeling off. The groove 52 is formedby pressing or etching, for example.

According to the embodiment, the molding resin 80 engages theindentation formed by the groove 52 at the portion of the molding resin80 that seals the periphery of the surface of the metal plate 50. Thatis, the groove 52 provides an anchor effect to prevent the molding resin80 from peeling off.

The groove 52 may be replaced by a protrusion from the surface of themetal plate 50. Basically, it just needs to form an indentation forproviding the anchor effect at the portion of the molding resin 80 thatseals the periphery of the surface of the metal plate 50.

Fourteenth Embodiment

FIGS. 28A and 28B show an electronic device according to the fourteenthembodiment. FIG. 28A is a schematic sectional view. FIG. 28B is aschematic plan view viewed from the bottom of FIG. 28A. According to theembodiment, the surface of the molding resin 80 protrudes outward fromthe surface of the metal plate 50 exposed from the molding resin 80 overthe second surface of the substrate 10.

As shown in FIGS. 28A and 28B, the electronic device according to theembodiment is provided with the molding resin 80 at the center and theperiphery of the electronic device over the second surface of thesubstrate 10. The molding resin at the center of the electronic deviceseals the second electronic component 30. The molding resin 80 providedfor the periphery includes itself only.

The part of the molding resin 80 at the periphery of the electronicdevice is thicker than the part of the molding resin 80 at the centerthereof. In FIGS. 28A and 28B, the thick molding resin 80 at theperiphery of the electronic device is shaped like a square frameequivalent to the periphery of the electronic device. The thin moldingresin 80 at the center thereof is shaped like an elongated rectanglewhen viewed in plan.

The thickness of the electronic device is equal to a distance betweenthe surface of the molding resin 80 over the first surface of thesubstrate 10 and the surface of the molding resin 80 over the secondsurface thereof. The embodiment provides the electronic device ofdifferent thickness partially. The periphery of the electronic device isthicker than the center thereof by dimension d as shown in FIG. 28A.

The embodiment partially changes the thickness of the molding resin 80provided over the second surface of the substrate 10. The molding resin80 can be easily provided with different thickness by adjusting a diefor the mold process. According to the embodiment, the periphery of theelectronic device is thicker than the center thereof, making it possibleto prevent the substrate 10 from warping.

Fifteenth Embodiment

The fifteenth embodiment describes various planar shapes of the moldingresin 80 provided for the second surface of the substrate 10.

FIGS. 29A, 29B, and 29C show first, second, and third examples of planarshapes for the molding resin 80 according to the embodiment. Theembodiment provides the planar shapes for the molding resin 80 and isapplicable to the above-mentioned embodiments.

As shown in FIGS. 29A to 29C, the substrate 10 according to theembodiment is a square plate in plan view. In FIGS. 29A to 29C, thesecond surface of the substrate 10 is exposed from the opening 80 awhere no molding resin 80 is used. The metal plate may be bonded to theexposed portion similarly to FIGS. 1A and 1B.

According to the first example in FIG. 29A, the strip-shaped moldingresin 80 is formed at the center and both sides over the second surfaceof the substrate 10 so as to extend between a pair of top and bottomopposite sides of the second surface of the substrate 10 in the verticaldirection.

According to the second example in FIG. 29B, the strip-shaped moldingresin 80 is formed like a cross so as to extend between a pair of topand bottom opposite sides of the second surface of the substrate 10 inthe vertical direction and between a pair of left and right oppositesides of the second surface of the substrate 10 in the horizontaldirection.

As shown in FIGS. 29A and 29B, the molding resin 80 provided on thesecond surface of the substrate 10 has the strip shape as a planar shapeextending between the pair of opposite sides of the second surface. Whenthe molding resin 80 is injected to the second surface of the substrate10, the molding resin 80 easily flows from one of the pair of oppositesides to the other on the second surface. The molding resin 80 can beinjected efficiently.

In addition, the molding resin 80 may have the planar shape according tothe third example as shown in FIG. 29C. It is to be distinctlyunderstood that the molding resin 80 may have the other planar shapesthan those shown in the above-mentioned examples.

Sixteenth Embodiment

The following describes the sixteenth embodiment with reference to theaccompanying drawings. FIGS. 31A and 31B show an electronic deviceaccording to the sixteenth embodiment. FIG. 31A is a sectional view.FIG. 31B is a schematic plan view of the electronic device viewed fromthe bottom of FIG. 31A.

The electronic device according to the embodiment includes a substrate310, a first electronic component 320, a second electronic component330, a metal plate 340, a lead frame 350, and a molding resin 360.

As shown in FIGS. 31A and 31B, the electronic device is a squareplate-shaped mold package. For example, the package size isapproximately 50×50×6.6 mm depending on the first electronic component320 and the second electronic component 330 mounted, a circuit scale, ortypes of the electronic components.

The substrate 310 shown in FIG. 31A is a plate-shaped wiring substrateincluding a first surface 311 and a second surface 312 opposite to thefirst surface 311. Circuit wiring is provided on the first surface 311of the substrate 310 and inside the same. The substrate 310 uses aceramic substrate, printed circuit board, and metal substrate, forexample. The electric circuit of the substrate 310 is connected to thelead frame 350 via a wire 370. The wire 370 uses a Au or Al bonding wireand is attached to the substrate 310 using normal wire bonding.

The first electronic component 320 is a precision component such as anLSI or a flip chip device mounted on the first surface 311 of thesubstrate 310. The first electronic component 320 is electricallyconnected to the electric circuit of the substrate 310 via a bump 321.An underfill 322 is filled between the first electronic component 320and the substrate 310. The underfill 322 is made of epoxy resinfunctioning as reinforcing resin.

The second electronic component 330 includes components such as a coil,power device, control device, capacitor, and oscillator mounted on thefirst surface 311 of the substrate 310. The second electronic component330 is electrically connected to the electric circuit of the substrate310 via a bonding wire such as Al and Au or a die mount material such assolder or electrically conductive adhesive. Unlike the first electroniccomponent 320 as a precision component, the second electronic component330 is resistive to influence such as deformation of the substrate 310.

The metal plate 340 is bonded to the second surface 312 of the substrate310 through an adhesive 341 so as to expose a portion of the secondsurface 312 of the substrate 310 projectively corresponding to the firstelectronic component 320 on the second surface 312. In other words, themetal plate 340 is bonded to a portion of the second surface 312 of thesubstrate 310 through the adhesive 341 other than the portion of thesecond surface 312 of the substrate 310 projecting the first electroniccomponent 320 onto the second surface 312. On the second surface 312 ofthe substrate 310, the metal plate 340 is not arranged at a positioncorresponding to the first electronic component 320. The metal plate 340is arranged so as to avoid the first electronic component 320.

As shown in FIG. 31B, the metal plate 340 is shaped into a squaredhorseshoe. Two metal plates 340 are provided. Both metal plates 340 arearranged to form a ring. A region is provided between the metal plates340 and contains no metal plate 340. A portion of the region enclosed ina dash-dot line corresponds to “the portion of the second surface 312 ofthe substrate 310 projecting the first electronic component 320 onto thesecond surface 312” mentioned above. This portion contains no metalplate 340.

In FIG. 31B, a dotted line around the metal plate 340 corresponds to anopening edge of the molding resin 360 beneath the electronic component.An arrow in FIG. 31B indicates an example location for a molding resingate 385 to be described later.

Each metal plate 340 is positioned correspondingly to a heater elementsuch as a power element belonging to the second electronic component 330mounted on the first surface 311 of the substrate 310. That is, themetal plate 340 also functions as a heat sink. The heater element isconnected to the electric circuit on the first surface 311 of thesubstrate 310 via Ag paste. For reliable heat transfer, the Ag pastepreferably indicates a thermal conductivity of greater than or equal to4 W/m·K.

A gap is provided between the two metal plates 340. The gap is used asan injection channel 361 for injecting resin to the above-mentionedportion when the molding resin 360 is molded.

The adhesive 341 bonds the metal plate 340 to the second surface 312 ofthe substrate 310. For example, the adhesive 341 uses silicone resin asa main component. In particular, the adhesive 341 preferably indicates athermal conductivity of greater than or equal to 4 W/m·K to reliablytransfer the heat of the substrate 310 to the metal plate 340.

The metal plate 340 and the lead frame 350 are made by pressing oretching a lead frame material. The metal plate 340 is configured as anisland for the lead frame material. The lead frame 350 is configured aswiring for electric connection to the outside. A thickness of the metalplate 340 is essentially equal to that of the lead frame 350.

The metal plate 340 and the lead frame 350 are mainly made of a Cu leadframe material in consideration for heat dissipation. However, there isa large difference between linear expansion coefficients for the Cu leadframe material and the substrate 310. A Fe material may be used for thepurpose of matching the linear expansion coefficients.

Specifically, a preferable lead frame material indicates linearexpansion coefficient a of smaller than or equal to 11 and Young'smodulus E of smaller than 200 GPa in consideration for consistency ofthe linear expansion coefficient with the substrate 310 and a stress atthe substrate edge. More preferably, the lead frame material may beconditioned to be a <9 GPa and E<150 GPa.

In consideration for weldability, the lead frame material may be platedwith PPF (Ni/Pd/Au) such as electrolytic nickel, Sn, and Au. Thematerial surface may be roughened to prevent the molding resin 360 frompeeling off.

The molding resin 360 is a resin member for sealing the substrate 310,the first electronic component 320, and the second electronic component330. Transfer mold technique is used to form the molding resin 360.

Specifically, the molding resin 360 seals not only the first surface 311of the substrate 310 but also the second surface 312 thereof so as toexpose the metal plate 340 as shown in FIG. 31B. The molding resin 360also seals a portion of the first surface 311 of the substrate 310 formounting the first electronic component 320 and a portion of the secondsurface 312 of the substrate 310 exposed from the metal plate 340 insandwich fashion.

The molding resin 360 just needs to seal only the portion of thesubstrate 310 in sandwich fashion so as not to deform the substrate 310or the first electronic component 320 due to a molding pressure of theresin. The embodiment aims to avoid deformation of the first electroniccomponent 320 as a precision component such as LSI. The molding resin360 sandwiches the portions of the substrate 310 on the first surface311 and the second surface 312 projecting the first electronic component320.

The molding resin 360 uses a mold material such as epoxy resin. Themolding resin 360 often uses a resin with heat expansion coefficient aranging between 8 and 14 for consistency of heat expansion coefficient abetween each member and the substrate 310. The resin needs to feature along gel time and low viscosity in consideration for filling efficiencyof the molding resin 360 on the second surface of the substrate 310. Themolding resin 360 preferably indicates a high glass transition point Tgfor use under a high temperature.

The following shows a preferred example of the molding resin 360. Foruse with the metal plate 340 and the lead frame 350 made of Cu, themolding resin 360 preferably indicates such properties as linearexpansion coefficient a1<17, Young's modulus E1<20 GPa, minimum meltviscosity <30 Pa·s (175° C.), gel time >20 seconds, and spiral flow >80cm. The molding resin 360 preferably indicates Tg<150° C. or morepreferably Tg<175° C. Further, the molding resin 360 preferablyindicates 10<a1<14, E1<17 GPa, and the minimum melt viscosity of 20(Pa·s) or less. Moreover, the molding resin 360 preferably indicates thegel time of shorter than 25 seconds and the spiral flow of 100 cm.

The lead frame 350 partially protrudes as an outer lead from the moldingresin 360. The outer leads enable electric connection between theelectronic device and the outside. There has been described the overallconfiguration of the electronic device according to the embodiment.

The following describes a manufacturing method of the electronic deviceshown in FIGS. 31A and 31B with reference to FIG. 32. FIG. 32 shows amanufacturing process of the electronic device shown in FIG. 32.

The first electronic component 320 and the second electronic component330 are mounted on the first surface 311 of the substrate 310 where anelectric circuit is formed. Wire bonding is conducted as needed. A leadframe material is pressed to form the metal plate 340 and the lead frame350. The metal plate 340 and the lead frame 350 are formed to becontinuous through dam bars.

The metal plate 340 is bonded to the second surface 312 of the substrate310 using the adhesive 341 so as to expose a portion of the secondsurface 312 of the substrate 310 projectively corresponding to the firstelectronic component 320. The wire is used to connect the substrate 310with the lead frame 350 through wire bonding. The process provides awork 380 of the electronic device in FIGS. 31A and 31B excluding themolding resin 360.

A molding apparatus is then used to form the molding resin 360. As shownin FIG. 32, the molding apparatus includes a lower mold 381 and an uppermold 382. The lower mold 381 and the upper mold 382 are combined to forma space 383 equivalent to an outer shape of the electronic device. Theupper mold 382 is provided with a plunger 384 for supplying the space383 with the molding resin 360. The molding resin 360 is introduced intothe space 383 from the plunger 384 through a molding resin gate 385. Theupper mold 382 and the lower mold 381 are provided with an air vent 386opposite to the molding resin gate 385 so as to exhaust air in the space383 to the outside.

The lower mold 381 is provided with a protrusion 387 that contacts withthe metal plate 340. The protrusion 387 contacts with the metal plate340 so that the metal plate 340 can be exposed from the molding resin360.

The prepared work 380 is placed on the lower mold 381 of the moldingapparatus. The lower mold 381 and the upper mold 382 are stacked witheach other. Thereafter, the molding resin 360 seals the first surface311 of the substrate 310. The molding resin 360 seals the second surface312 of the substrate 310 so as to expose the metal plate 340. To dothis, the molding resin 360 is supplied from the plunger 384 and flowstoward the first surface 311 and the second surface 312 of the metalplate 310.

The molding resin 360 flows through the second surface 312 of thesubstrate 310 and also passes through the injection channel 361 as shownin FIG. 31B. The molding resin 360 is also filled in the portion of thesecond surface 312 of the substrate 310 projectively corresponding tothe first electronic component 320.

The molding resin 360 is filled in the space 383 to seal the firstsurface 311 and the second surface 312 of the substrate 310. A moldingpressure of the molding resin 360 is applied to the work 380. At theportion of the substrate 310 provided with the first electroniccomponent 320, the molding resin 360 seals the portion of the firstsurface 311 of the substrate 310 for mounting the first electroniccomponent 320 and the portion of the second surface 312 of the substrate310 exposed from the metal plate 340 in sandwich style.

The molding pressure of the molding resin 360 is uniformly applied fromboth the first surface 311 and the second surface 312 of the substrate310. Therefore, the substrate 310 is not subjected to a molding pressuredeflecting to the first surface 311 or the second surface 312. Thesubstrate 310 or the first electronic component 320 is not deformed by adeflected molding pressure. Subsequently, dam bars are removed tocomplete the electronic device in FIGS. 31A and 31B.

As mentioned above, the embodiment seals the portion of the firstsurface 311 of the substrate 310 for mounting the first electroniccomponent 320 and the portion of the second surface 312 of the substrate310 exposed from the metal plate 340 in sandwich style.

The portion of the substrate 310 provided with the first electroniccomponent 320 is subjected to a molding pressure of the molding resin360 uniformly from the first surface 311 and the second surface 312 ofthe substrate 310. The structure can be subjected to the uniform moldingpressure. Accordingly, the structure is not subjected to a forcedeflecting to the first surface 311 or the second surface 312 of thesubstrate 310. The portion of the substrate 310 provided with the firstelectronic component 320 can be prevented from deformation of thesubstrate 310 or the first electronic component 320 as a precision part.

The first electronic component 320 is equivalent to an electroniccomponent.

Seventeenth Embodiment

The following describes only differences between the seventeenth andsixteenth embodiments. FIG. 33 is a schematic plan view of theelectronic device according to the seventeenth embodiment viewed fromthe bottom of the electronic device and corresponds to FIG. 31B. In FIG.33, a dotted line around the metal plate 340 corresponds to an openingedge of the molding resin 360 beneath the electronic component.

As shown in FIG. 33, the metal plate 340 is rectangular when viewed inplan. The two metal plates 340 are arranged with an interval. Theinterval is larger than the size of the first electronic component 320.The metal plate 340 is not arranged at a portion of the second surface312 of the substrate 310 projectively corresponding to the firstelectronic component 320. That portion is provided with the moldingresin 360.

According to the planar shape and the arrangement of the metal plate340, the injection channel 361 for the molding resin 360 is wider thanthe injection channel 361 in FIG. 31B. The molding resin 360 can bepositively supplied to the second surface 312 of the substrate 310,improving injection efficiency of the molding resin 360.

Eighteenth Embodiment

The following describes differences between the eighteenth embodimentand the sixteenth and seventeenth embodiments. FIG. 34 is a schematicplan view of the electronic device according to the eighteenthembodiment viewed from the bottom of the electronic device andcorresponds to FIG. 31B. In FIG. 34, a dotted line around the metalplate 340 corresponds to an opening edge of the molding resin 360beneath the electronic component.

As shown in FIG. 34, the metal plate 340 is approximately square whenviewed in plan. The four metal plates 340 are arranged so as to bepositioned to apexes of a virtual quadrangle. None of the metal plates340 is arranged to a portion of the second surface 312 of the substrate310 projectively corresponding to the first electronic component 320.Each of the metal plates 340 is bonded to the second surface 312 of thesubstrate 310 so as to expose the portion of the second surface 312 ofthe substrate 310 projectively corresponding to the first electroniccomponent 320.

The embodiment separately arranges the four metal plates 340. Themolding resin 360 is accordingly arranged between the metal plates 340.The second surface 312 of the substrate 310 can be provided with moremolding resins 360 than the examples of FIG. 31B and FIG. 33.

When the molding resin 360 shrinks and reaches a lower temperature,there is available approximately one-to-one correspondence between theamount of the molding resin 360 on the second surface 312 and that ofthe molding resin 360 on the first surface 311 of the substrate 310 withreference to the lead frame 350 or the substrate 310. The electronicdevice can be structured to provide reduced warpage.

Nineteenth Embodiment

The following describes differences between the nineteenth embodimentand the sixteenth through eighteenth embodiments. FIGS. 35A and 35B showan electronic device according to the nineteenth embodiment. FIG. 35A isa sectional view. FIG. 35B is a schematic plan view of the electronicdevice viewed from the bottom of FIG. 35A. In FIG. 35B, a dotted linearound the metal plate 340 corresponds to an opening edge of the moldingresin 360 beneath the electronic component.

As shown in FIG. 35A, the embodiment does not mount the first electroniccomponent 320 on an inner edge of the first surface 311 of the substrate310 but toward one of the lead frames 350. The second electroniccomponent 330 is accordingly arranged toward the other lead frame 350opposite to the first electronic component 320 on the first surface 311of the substrate 310.

As shown in FIG. 35B, the metal plate 340 is not arranged at the portionof the second surface 312 of the substrate 310 projectivelycorresponding to the first electronic component 320. The metal plate 340is bonded to the second surface 312 of the substrate 310 correspondingto the arrangement position of the second electronic component 330.According to the embodiment, the metal plate 340 is rectangular whenviewed in plan. The metal plate 340 is arranged so as to deflect to theother lead frame 350.

As mentioned above, the metal plate 340 can be freely arranged inaccordance with a location on the first surface 311 of the substrate 310for mounting the first electronic component 320 as a precision part.

Twentieth Embodiment

The following describes differences between the twentieth embodiment andthe sixteenth through nineteenth embodiments. FIG. 36 is a schematicplan view of the electronic device according to the twentiethembodiment. As shown in FIG. 36, the molding resin 360 covers an outeredge 342 of the metal plate 340.

The molding resin 360 can cover the outer edge 342 of the metal plate340 using the protrusion 387 of the lower mold 381 in the moldingapparatus such that an area of the protrusion 387 in contact with themetal plate 340 is smaller than the metal plate 340.

As mentioned above, the molding resin 360 can cover the outer edge 342of the metal plate 340 so as to wrap around the outer edge 342. It ispossible to prevent the molding resin 360 from peeling off the metalplate 340.

Twenty-First Embodiment

The following describes differences between the twenty-first embodimentand the sixteenth through twentieth embodiments. FIG. 37 is a schematicplan view of the electronic device according to the twenty-firstembodiment. As shown in FIG. 37, the height of the molding resin 60differs from that in FIG. 31A on the second surface 312 of the substrate310.

Specifically, the molding resin 360 is provided at the portion of thesecond surface 312 of the substrate 310 projectively corresponding tothe first electronic component 320. In this case, the molding resin 60is higher than the metal plate 340 with reference to the second surface312 of the substrate 310. This portion of the molding resin 360 is lowerthan the highest portion of the molding resin 360 formed on the secondsurface 312 of the substrate 310.

The height of the molding resin 360 can be adjusted by changing theshape of the lower mold 381 in the molding apparatus. The height of themolding resin 360 can be changed freely. The structure can minimizepossibility of a weld that is otherwise often generated on the secondsurface 312 where the molding resin 360 is injected inefficiently.

Adjusting the height of the molding resin 360 can also adjust a speed ofinjecting the molding resin 360 on the second surface 312 of thesubstrate 310. The work 380 placed in the lower mold 381 and the uppermold 382 can allow the same injection speed of the molding resin 360 onthe first surface 311 and the second surface 312 of the substrate 310.It is possible to fill the molding resin 360 in the space 383 betweenthe lower mold 381 and the upper mold 382 without leaving air in thespace 383.

Since no air remains in the space 383, a uniform molding pressure can beapplied to the first surface 311 and the second surface 312 of thesubstrate 310 simultaneously during the resin seal.

Twenty-Second Embodiment

The following describes differences between the twenty-second embodimentand the sixteenth through twenty-first embodiments. FIG. 38 is aschematic plan view of the electronic device according to thetwenty-second embodiment. As shown in FIG. 38, the molding resin 360 isas high as the metal plate 340 on the second surface 312 of thesubstrate 310.

Specifically, the molding resin 360 is provided at the portion of thesecond surface 312 of the substrate 310 projectively corresponding tothe first electronic component 320. In this case, the molding resin 360is as high as the metal plate 340 with reference to the second surface312 of the substrate 310. This portion of the molding resin 360 is ashigh as the highest portion of the molding resin 360 formed on thesecond surface 312 of the substrate 310.

According to the embodiment, the metal plate 340 is thicker than thatshown in FIGS. 31A and 31B so that the metal plate 340 is as high as themolding resin 360. For example, a differently shaped material is used asthe metal plate 340. Different materials may be used for the metal plateand the lead frame 350.

Since the electronic device has a leveled height on the second surface312 of the substrate 310, there is no need to conform the shape ofanother member for mounting the electronic device to the electronicdevice. The electronic device can be easily attached to the othermembers.

Twenty-Third Embodiment

The following describes differences between the twenty-third embodimentand the sixteenth through twenty-second embodiments. FIG. 39 is aschematic plan view of the electronic device according to thetwenty-third embodiment. As shown in FIG. 39, the substrate 310 containsthe first electronic component 320 such as LSI.

The substrate 310 is laminated, for example. The first electroniccomponent 320 contained in the substrate 310 is connected to wiringformed inside the substrate 310 for functioning. The first surface 311of the substrate 310 is mounted with only the second electroniccomponent 330.

The metal plate 340 is bonded to the second surface 312 of the substrate310 so as to expose the portion of the second surface 312 of thesubstrate 310 projectively corresponding to the first electroniccomponent 320. In this case, the metal plate 340 is arranged at aposition corresponding to the second electronic component 330 on thesecond surface 312 of the substrate 310. The metal plate dissipates heatfrom the second electronic component 330 through the substrate 310.

When the substrate 310 contains the first electronic component 320 asmentioned above, the molding resin 360 also seals the portion of thefirst surface 311 of the substrate 310 projectively corresponding to thefirst electronic component 320 and the portion of the second surface 312of the substrate 310 exposed from the metal plate 340 in sandwich style.A molding pressure is uniformly applied to the portion of the substrate310 for arranging the first electronic component 320 from the firstsurface 311 and the second surface 312 of the substrate 310. Thesubstrate 310 is not deformed.

Twenty-Fourth Embodiment

The following describes differences between the twenty-fourth embodimentand the sixteenth through twenty-third embodiments. While there havebeen described the embodiments that are structured to bond the metalplate 340 to the second surface 312 of the substrate 310 using theadhesive 341, the twenty-fourth embodiment will describe a structurethat does not use the metal plate 340.

FIG. 40 is a schematic plan view of the electronic device according tothe twenty-fourth embodiment. As shown in FIG. 40, the electronic deviceincludes a ceramic substrate 390, the first electronic component 320,the second electronic component 330, the lead frame 350, and the moldingresin 360.

The ceramic substrate 390 includes a first surface 391 and a secondsurface 392 opposite to the first surface 391 and contains a wiringlayer inside. The first electronic component 320 and the secondelectronic component 330 are mounted on the first surface 391 of theceramic substrate 390. The metal plate 340 used for the above-mentionedembodiments are unnecessary because the ceramic substrate 390 featureshigh radiation performance. Similarly to the sixteenth embodiment, anelectric circuit on the ceramic substrate 390 is connected with the leadframe 350 through the wire 370.

The molding resin 360 seals the first surface 391 and the second surface392 of the ceramic substrate 390 so as to expose an inner edge 392 a ofthe second surface 392 of the ceramic substrate 390. Further, themolding resin 360 seals an outer edge 391 a of the first surface 391 ofthe ceramic substrate 390 and an outer edge 392 b of the second surface392 of the ceramic substrate 390 in sandwich style.

The sealing is used for the following reason. As mentioned above, theceramic substrate 390 contains the wiring layer inside. The ceramicsubstrate 390 warps at the outer edges 391 a and 392 b where a wiringdensity is low. A gap occurs between the lower mold 381 and the outeredge 391 a of the ceramic substrate 390. When a molding pressure isapplied to the outer edges 391 a and 392 b of the ceramic substrate 390,the outer edges 391 a and 392 b warp. The lower mold 381 presses thewarped outer edges 391 a and 392 b. The ceramic substrate 390 is finallybroken. To solve this problem, the first surface 391 and the secondsurface 392 of the ceramic substrate 390 seal the outer edges 391 a and392 b thereof in sandwich style as described in this embodiment. Amolding pressure is uniformly applied to the first surface 391 and thesecond surface 392 of the ceramic substrate 390, preventing the outeredges 391 a and 392 b thereof from being deformed and broken. Further,the embodiment solves such problem that the outer edges 391 a and 392 bof the ceramic substrate 390 slightly warp to let the molding resin 390ooze onto the second surface 392 of the ceramic substrate 390 and causea burr to be formed.

As a manufacturing method of the above-mentioned electronic device, awork is prepared so that the first electronic component 320 and thesecond electronic component 330 are mounted on the first surface 391 ofthe ceramic substrate 390. Using the molding apparatus, the moldingresin 360 seals the first surface 391 and the second surface 392 of theceramic substrate 390 so as to expose the inner edge 392 a of the secondsurface 392 thereof. For this purpose, the protrusion 387 of the lowermold 381 just needs to contact the inner edge 392 a of the secondsurface 392 of the ceramic substrate 390.

In order to seal the ceramic substrate 390 with the molding resin asmentioned above, the molding resin 360 seals the outer edge 391 a of thefirst surface of the ceramic substrate 390 and the outer edge 392 b ofthe second surface 392 thereof in sandwich style. A molding pressure ofthe molding resin 360 can be uniformly applied to the outer edges 391 aand 392 a of the ceramic substrate 390 from both the first surface 391and the second surface 392 of the ceramic substrate 390. It is possibleto prevent: a deflected force from being applied to the outer edges 391a and 392 b of the ceramic substrate 390; the outer edges 391 a and 392b from being warped; and the ceramic substrate 390 or the firstelectronic component 320 from being deformed.

As mentioned above, the outer edges 391 a and 392 b of the ceramicsubstrate 390 are subjected to warpage. The molding resin 360 may wrapthe outer edges 391 a and 392 b so as to expose the inner edge 392 a ofthe second surface 392 of the ceramic substrate 390 from the moldingresin 360 for heat dissipation. The ceramic substrate 390 can beprevented from being deformed or destroyed.

Twenty-Fifth Embodiment

The following describes differences between the twenty-fifth embodimentand the twenty-fourth embodiment. FIG. 41 is a schematic plan view ofthe electronic device according to the twenty-fifth embodiment. As shownin FIG. 41, the embodiment also provides the molding resin 360 for theinner edge 392 a of the second surface 392 of the ceramic substrate 390.The molding resin 360 is positioned to a portion of the inner edge 392 aof the second surface 392 of the ceramic substrate 390 projectivelycorresponding to the first electronic component 320.

According to this structure, the ceramic substrate 390 is sandwichedbetween the molding resin 360 on the first surface 391 and the secondsurface 392 of the ceramic substrate 390 at the inner edge 392 a of thesecond surface 392 of the ceramic substrate 390. A uniform moldingpressure is applied to the first surface 391 and the second surface 392of the ceramic substrate 390. The ceramic substrate 390 is more unlikelydeformed.

In particular, the ceramic substrate 390 is sandwiched between the firstsurface 391 and the second surface 392 of the ceramic substrate 390 atthe location of the inner edge 392 a of the second surface 392 of theceramic substrate 390. It is possible to prevent deformation of theceramic substrate 390 but also destruction of the first electroniccomponent 320 due to a molding pressure of the molding resin 360.

The shape of the protrusion 387 of the lower mold 381 for the moldingapparatus may be changed to provide the molding resin 360 also for theinner edge 392 a of the second surface 392 of the ceramic substrate 390.

Twenty-Sixth Embodiment

The following describes differences between the twenty-sixth embodimentand the twenty-fourth and twenty-fifth embodiments. FIG. 42 is aschematic plan view of the electronic device according to thetwenty-sixth embodiment. As shown in FIG. 42, only the second electroniccomponent 330 is mounted on the first surface 391 of the ceramicsubstrate 390. The first electronic component 320 is mounted on theinner edge 392 a of the second surface 392 of the ceramic substrate 390.

The first electronic component 320 can be mounted on the ceramicsubstrate 390 even when a component inappropriate for molding is used asthe first electronic component 320. The first electronic component 320inappropriate for molding includes MEMS, aluminum electrolyticcapacitor, tantalum capacitor, and coil component.

Since the first electronic component 320 is mounted on a portion exposedfrom the molding resin 360, the first electronic component 320inappropriate for molding is prevented from characteristic degradationor failure due to a molding pressure of the molding resin 360.

In addition, the first electronic component 320 is covered with aprotection film 323. The protection film 323 uses resin, for example.The protection film 323 protects the first electronic component 320independently of the molding resin 360.

As a manufacturing method of the above-mentioned electronic device, thesecond electronic component 330 is mounted on the first surface 391 ofthe ceramic substrate 390. As mentioned above, the molding resin 360seals the electric circuit on the ceramic substrate 390 and the leadframe 350 that are connected with each other through the wire 370.

The first electronic component 320 is mounted on the inner edge 392 a ofthe second surface 392 of the ceramic substrate 390. Finally, theprotection film 323 covers the first electronic component 320 tocomplete the electronic device as shown in FIG. 42.

Other Embodiments

While FIGS. 31A, 31B, 33, and 34 show the structures using multiplemetal plates 340, one of the metal plates 340 may have an openingprojectively corresponding to the first electronic component 320.

The sixteenth through twenty-third embodiments bond the metal plate 340to the second surface 312 of the substrate 310. The reason is totransfer the heat of the substrate 310 to the metal plate 340 anddissipate the heat outside. However, the metal plate 340 may not be usedwhen radiation performance of the substrate 310 can be improved usingthermal via holes. In this case, the substrate 310 can employ a wiringsubstrate such as a printed substrate.

The molding resin gate 385 shown in FIGS. 31B, 33, and 34 is positionedto a corner of the electronic device. This is just an example. Asanother example, the molding resin gate 385 may be positioned to theside of the electronic device.

The twenty-sixth embodiment shows the structure of covering the firstelectronic component 320 with the protection film 323. The protectionfilm 323 may not be provided.

The above disclosure has the following aspects.

According to a first aspect of the present disclosure, an electronicdevice includes: a substrate having first and second surfaces, whereinthe first surface is opposite to the second surface; a first electronicelement mounted on the first surface of the substrate; a secondelectronic element mounted on the second surface of the substrate; and aresin mold sealing the first electronic element and the first surface ofthe substrate. The resin mold further seals the second electronicelement on the second surface of the substrate. The second surface ofthe substrate has a portion, which is exposed from the resin mold. Thesecond electronic element is not disposed on the portion of the secondsurface.

According to this configuration, the resin mold is injected to theportion of the second surface of the substrate corresponding to thesecond electronic element when the resin mold is used to seal the firstand second electronic elements. The configuration decreases a stress ofthe resin mold on the ceramic substrate from the first surface of thesubstrate in comparison with a conventional technique that providessealing by applying an adhesive softer than a molding resin to thesecond surface of a ceramic substrate. As a result, it is possible toprevent the substrate from cracking during a mold process. Thus, amolding resin stress applied on the substrate from one surface of thesubstrate during a mold process is reduced. The mold process is used fora half molded electronic device that includes the first electronicelement mounted on the first surface of the substrate and the secondelectronic element mounted on the second surface thereof.

Alternatively, the electronic device may further include: a metal platebonded to the portion of the second surface of the substrate via anadhesive. The metal plate has a surface opposite to the second surface,and the surface of the metal plate is exposed from the resin mold. Inthis manner, the radiation performance improves through the metal plate.

Further, the second surface of the substrate may further include asecond portion, which is covered with the resin mold. The secondelectronic element is not disposed on the second portion of the secondsurface, and the resin mold on the second portion of the second surfaceprotrudes outward from the surface of the metal plate. Furthermore, aperiphery of the surface of the metal plate may be sealed with the resinmold. It is possible to decrease a stress on an interface between themetal plate and the resin mold to improve an effect of preventing theresin mold from peeling off the metal plate. Further, the periphery ofthe surface of the metal plate may include an indentation for preventingthe resin mold from peeling off, and the indentation of the metal platemay be sealed with the resin mold. The resin mold can be prevented frompeeling off that portion.

Alternatively, the portion of the second surface may be disposed arounda center of the substrate, and the second portion of the second surfaceis disposed on a periphery of the substrate, and the resin mold on thesecond portion of the second surface may be thicker than the resin moldon the second electronic element. It is expected to prevent thesubstrate from warping because the electronic device is thicker at thecenter than at the periphery.

Alternatively, a surface of the resin mold on the second electronicelement may be disposed on a same plane as the surface of the metalplate. The metal plate is able to easily contact with an external heatdissipation member.

Alternatively, the substrate may have a square plate shape, and theresin mold on the second electronic element may have a stripe shapeextending from one side of the square plate shape to an opposite side.When the resin mold is injected to the second surface of the substrate,the resin mold easily flows from one of the pair of opposite sides tothe other on the second surface. It is possible to more efficientlyinject the resin mold.

According to a second aspect of the present disclosure, an electronicdevice includes: a ceramic substrate having first and second surfaces,wherein the first surface is opposite to the second surface; a firstelectronic element mounted on the first surface of the ceramicsubstrate; a metal plate bonded to a first portion of the second surfaceof the ceramic substrate via an adhesive; a second electronic elementmounted on a second portion of the second surface of the ceramicsubstrate; and a resin mold sealing the ceramic substrate and the firstand second electronic elements so as to expose the metal plate. Thefirst portion of the second surface is different from the second portionof the second surface.

According to this configuration, the resin mold is injected to theportion of the second surface of the ceramic substrate corresponding tothe second electronic element when the resin mold is used to seal thefirst and second electronic elements. The configuration decreases astress of the resin mold on the ceramic substrate from the first surfaceof the substrate in comparison with a conventional technique thatprovides sealing by applying an adhesive softer than a molding resin tothe second surface of a ceramic substrate. As a result, it is possibleto prevent the ceramic substrate from cracking during a mold process.

Alternatively, the metal plate may not cover the second electronicelement.

Alternatively, the metal plate may cover the second electronic elementvia the resin mold.

Alternatively, the second portion of the second surface may be aconcavity with a bottom, and the second electronic element may bemounted on the bottom of the concavity. It is possible to reduceprotrusion of the second electronic element over the second surface ofthe ceramic substrate and keep the size of the electronic device assmall as possible in the thickness direction of the ceramic substrate.

According to a third aspect of the present disclosure, a manufacturingmethod of an electronic device includes: mounting a first electronicelement on a first surface of a ceramic substrate; bonding a metal plateto a first portion of a second surface the ceramic substrate, whereinthe second surface is opposite to the first surface; mounting a secondelectronic element on a second portion of the second surface of theceramic substrate, wherein the second portion of the second surface isdifferent from the first portion of the second surface; and sealing theceramic substrate and the first and second electronic elements with aresin mold so as to expose the metal plate. The metal plate is bonded tothe ceramic substrate via an adhesive. The second portion of the secondsurface is different from the first portion of the second surface, andthe first and second electronic elements are simultaneously sealed withthe resin mold.

According to this configuration, the resin mold is injected to both thefirst surface and second surface of the ceramic substrate when the resinmold is used to seal the first and second electronic elements. Theconfiguration decreases a stress of the resin mold on the ceramicsubstrate from the first surface of the substrate in comparison with aconventional technique that provides sealing by applying an adhesivesofter than a molding resin to the second surface of a ceramicsubstrate. As a result, it is possible to prevent the ceramic substratefrom cracking during a mold process.

According to a fourth aspect of the present disclosure, a manufacturingmethod of an electronic device includes: mounting a first electronicelement on a first surface of a ceramic substrate; bonding a metal plateto a first portion of a second surface of the ceramic substrate, whereinthe second surface is opposite to the first surface; mounting a secondelectronic element on a second portion of the second surface of theceramic substrate, wherein the second portion of the second surface isdifferent from the first portion of the second surface; sealing theceramic substrate and the first electronic element with a first resinmold so as to expose the metal plate; and sealing the second electronicelement with a second resin mold at a molding temperature equal to amolding temperature of the first resin mold. The second resin mold hasYoung's modulus equal to or larger than 100 MPa, and the metal plate isbonded to the ceramic substrate via an adhesive.

According to this configuration, the portion of the second surface ofthe ceramic substrate corresponding to the second electronic element isprovided with the sealing resin mold indicating Young's modulus of 100MPa or more at a molding temperature of the resin mold for sealing whenthe resin mold is used to seal the first electronic element. Theconfiguration decreases a stress of the resin mold on the ceramicsubstrate from the first surface of the substrate in comparison with aconventional technique that provides sealing by applying an adhesivesofter than a molding resin to the second surface of a ceramicsubstrate. As a result, it is possible to prevent the ceramic substratefrom cracking during a mold process.

According to a fifth aspect of the present disclosure, a manufacturingmethod of an electronic device includes: mounting a first electronicelement on a first surface of a ceramic substrate; bonding a metal plateto a first portion of a second surface of the ceramic substrate, whereinthe second surface is opposite to the first surface; mounting a secondelectronic element on a second portion of the second surface of theceramic substrate, wherein the second portion of the second surface isdifferent from the first portion; sealing the ceramic substrate, themetal plate and the first and second electronic elements with a resinmold; and removing a portion of the resin mold to expose the metalplate. The metal plate is bonded to the ceramic substrate via anadhesive.

The configuration decreases a stress of the resin mold on the ceramicsubstrate from the first surface of the substrate because the resin moldseals the entire of the ceramic substrate. As a result, it is possibleto prevent the ceramic substrate from cracking during a mold process.

Alternatively, the manufacturing method may further include: forming aconcavity on the second portion of the second surface of the ceramicsubstrate. The second electronic element is mounted on a bottom of theconcavity.

According to a sixth aspect of the present disclosure, an electronicdevice includes: a substrate that includes a first surface and a secondsurface opposite to the first surface; an electronic element mounted ona first portion of the first surface of the substrate; a metal platebonded to the second surface of the substrate so as to expose a secondportion of the second surface of the substrate opposite to theelectronic element; and a resin mold that seals the first surface of thesubstrate and seals the second surface of the substrate so as to exposethe metal plate. The resin mold sandwiches the first portion of thefirst surface and the second portion of the second surface of thesubstrate.

According to the above device, the portion of the substrate for mountingthe electronic element is uniformly applied with a molding pressure ofthe resin mold from both the first surface and the second surface of thesubstrate. The substrate can be structured to prevent a deflected forcefrom being applied. It is possible to prevent deformation of thesubstrate and the electronic element. Thus, a structure is provided suchthat the structure prevents the substrate from being deformed due to amolding pressure of resin mold.

According to a seventh aspect of the present disclosure, an electronicdevice includes: a substrate that includes a first surface and a secondsurface opposite to the first surface; an electronic element disposed inthe substrate; wherein the first surface includes a first portioncorresponding to the electronic element; a metal plate bonded to asecond surface of the substrate so as to expose a second portion of thesecond surface of the substrate opposite to the first portion of thefirst surface; and a resin mold that seals the first surface of thesubstrate and seals the second surface of the substrate so as to exposethe metal plate. The resin mold sandwiches the first portion of thefirst surface and the second portion of the second surface of thesubstrate.

According to the above device, the portion of the substrate for mountingthe electronic element is uniformly applied with a molding pressure ofthe resin mold from both the first surface and the second surface of thesubstrate. The substrate can be structured to prevent a deflected forcefrom being applied. It is possible to prevent deformation of thesubstrate and the electronic element. Thus, a structure is provided suchthat the structure prevents the substrate from being deformed due to amolding pressure of resin mold.

Alternatively, the resin mold may cover an outer edge of the metalplate. It is possible to prevent the resin mold from peeling off themetal plate.

Alternatively, the second surface of the substrate may further include athird portion, which is covered with the resin mold. The metal plate isnot disposed on the third portion of the second surface. The metal platehas a first height from the second surface of the substrate. The resinmold disposed on the second portion of the second surface has a secondheight from the second surface of the substrate. The resin mold disposedon the third portion of the second surface has a third height from thesecond surface of the substrate. The second height is larger than thefirst height, and smaller than the third height.

The above structure makes it possible to adjust a speed of injecting theresin mold on the second surface of the substrate during manufacture ofthe electronic device. A uniform molding pressure can be simultaneouslyapplied to the first surface and the second surface of the substrateduring resin seal. The substrate can be structured to prevent adeflected force from being applied.

Alternatively, the second surface of the substrate may further include athird portion, which is covered with the resin mold. The metal plate isnot disposed on the third portion of the second surface. The metal platehas a first height from the second surface of the substrate. The resinmold disposed on the second portion of the second surface has a secondheight from the second surface of the substrate. The resin mold disposedon the third portion of the second surface has a third height from thesecond surface of the substrate. The first, second and third heights areequal to each other.

The second surface of the substrate ensures the same height and isstructured to be flat. The electronic device can be easily mounted tothe other members.

According to an eighth aspect of the present disclosure, an electronicdevice includes; a ceramic substrate having a first surface and a secondsurface opposite to the first surface; an electronic element is mountedon the first surface; and a resin mold that seals the first surface ofthe ceramic substrate and seals the second surface of the ceramicsubstrate so as to expose an inner portion of the second surface. Thefirst surface has an outer edge, and the second surface has an outeredge, and the resin mold sandwiches the outer edge of the first surfaceand the outer edge of the second surface.

According to the above structure, a molding pressure of the resin moldis uniformly applied from both the first surface and the second surfaceof the ceramic substrate at outer edges of the ceramic substrate. Thestructure can prevent a deflected force from being applied to the outeredges of the ceramic substrate where the outer edges easily warp. It ispossible to prevent deformation of the ceramic substrate and theelectronic element.

Alternatively, the inner portion of the second surface may include aportion, on which the resin mold covers.

According to this structure, the ceramic substrate is sandwiched betweenthe resin mold on the first surface and the resin mold on the secondsurface of the ceramic substrate. A uniform molding pressure is appliedto the first surface and the second surface of the ceramic substrate atthe inner portion on the second surface of the ceramic substrate.

In particular, the portion of the ceramic substrate for mounting theelectronic element is sandwiched between the resin mold on the firstsurface and the second surface. It is possible to prevent the electronicelement from being destroyed by a molding pressure of the resin mold.

According to a ninth aspect of the present disclosure, an electronicdevice includes: a ceramic substrate having a first surface and a secondsurface opposite to the first surface; an electronic element mounted onan inner portion of the second surface; and a resin mold that seals thefirst surface of the ceramic substrate and seals the second surface ofthe ceramic substrate so as to expose the electronic element and theinner portion of the second surface. The first surface has an outer edge(391 a), and the second surface has an outer edge (392 b), and the resinmold sandwiches the outer edge of the first surface and the outer edgeof the second surface.

The above structure can uniformly apply a molding pressure of the resinmold from both the first surface and the second surface of the ceramicsubstrate at the outer edges of the ceramic substrate. The electronicelement inappropriate for molding can be prevented from characteristicdegradation or failure due to a molding pressure of the resin mold.

Alternatively, the electronic element may be covered with a protectionfilm. The electronic element can be protected independently of the resinmold.

According to a tenth aspect of the present disclosure, a manufacturingmethod of an electronic device includes: mounting an electronic elementon a first portion of a first surface of a substrate; bonding a metalplate on a second surface of the substrate so as to expose a secondportion of the second surface of the substrate opposite to theelectronic element; wherein the second surface is opposite to the firstsurface; and sealing the first surface of the substrate and the secondsurface of the substrate with a resin mold so as to expose the metalplate. The resin mold sandwiches the first portion of the first surfaceand the second portion of the second surface of the substrate.

According to the above method, a molding pressure of the resin mold canbe applied to the portion of the substrate for mounting the electronicelement from both the first surface and the second surface of thesubstrate. The structure can prevent a deflected force from beingapplied to the substrate and prevent deformation of the substrate andthe electronic element.

According to an eleventh aspect of the present disclosure, amanufacturing method of an electronic device includes: forming anelectronic element in a substrate; wherein the substrate includes afirst surface and a second surface opposite to the first surface; andthe first surface includes a first portion corresponding to theelectronic element; bonding a metal plate to the second surface of thesubstrate so as to expose a second portion of the second surface of thesubstrate opposite to the first portion of the first surface; andsealing the first surface of the substrate and the second surface of thesubstrate with a resin mold so as to expose the metal plate. The resinmold sandwiches the first portion of the first surface and the secondportion of the second surface of the substrate.

According to the above method, a molding pressure of the resin mold canbe applied to the portion of the substrate for mounting the electronicelement from both the first surface and the second surface of thesubstrate. The structure can prevent a deflected force from beingapplied to the substrate and prevent deformation of the substrate andthe electronic element.

According to a twelfth aspect of the present disclosure, a manufacturingmethod of an electronic device includes: mounting an electronic elementon a first surface of a ceramic substrate; wherein the ceramic substratehas the first surface and a second surface opposite to the firstsurface; and sealing the first surface of the ceramic substrate and thesecond surface of the ceramic substrate with a resin mold so as toexpose an inner portion of the second surface. The first surface has anouter edge (391 a), and the second surface has an outer edge (392 b),and the resin mold sandwiches the outer edge of the first surface andthe outer edge of the second surface.

According to the structure, a molding pressure of the resin mold isuniformly applied from both the first surface and the second surface ofthe ceramic substrate at outer edges of the ceramic substrate. Thestructure can prevent a deflected force from being applied to the outeredges of the ceramic substrate where the outer edges easily warp. It ispossible to prevent deformation of the ceramic substrate and theelectronic element.

According to a thirteenth aspect of the present disclosure, amanufacturing method of an electronic device includes: mounting anelectronic element on an inner portion of a second surface of a ceramicsubstrate; wherein the ceramic substrate has a first surface and thesecond surface opposite to the first surface; sealing the first surfaceof the ceramic substrate and the second surface of the ceramic substratewith a resin mold so as to expose the electronic element and the innerportion of the second surface. The first surface has an outer edge (391a), and the second surface has an outer edge (392 b), and the resin moldsandwiches the outer edge of the first surface and the outer edge of thesecond surface.

A molding pressure of the resin mold can be uniformly applied to theouter edges from both the first surface and the second surface of theceramic substrate. Accordingly, the ceramic substrate can be preventedfrom deformation. Since the electronic element inappropriate for moldingis not sealed with the resin mold, it is possible to prevent theelectronic element from characteristic degradation or failure due to amolding pressure of the resin mold.

While the invention has been described with reference to preferredembodiments thereof, it is to be understood that the invention is notlimited to the preferred embodiments and constructions. The invention isintended to cover various modification and equivalent arrangements. Inaddition, while the various combinations and configurations, which arepreferred, other combinations and configurations, including more, lessor only a single element, are also within the spirit and scope of theinvention.

1-12. (canceled)
 13. A manufacturing method of an electronic devicecomprising: mounting a first electronic element on a first surface of aceramic substrate; bonding a metal plate to a first portion of a secondsurface the ceramic substrate, wherein the second surface is opposite tothe first surface; mounting a second electronic element on a secondportion of the second surface of the ceramic substrate, wherein thesecond portion of the second surface is different from the first portionof the second surface; and sealing the ceramic substrate and the firstand second electronic elements with a resin mold so as to expose themetal plate, wherein the metal plate is bonded to the ceramic substratevia an adhesive, wherein the second portion of the second surface isdifferent from the first portion of the second surface, and wherein thefirst and second electronic elements are simultaneously sealed with theresin mold.
 14. A manufacturing method of an electronic devicecomprising: mounting a first electronic element on a first surface of aceramic substrate; bonding a metal plate to a first portion of a secondsurface of the ceramic substrate, wherein the second surface is oppositeto the first surface; mounting a second electronic element on a secondportion of the second surface of the ceramic substrate, wherein thesecond portion of the second surface is different from the first portionof the second surface; sealing the ceramic substrate and the firstelectronic element with a first resin mold so as to expose the metalplate; and sealing the second electronic element with a second resinmold at a molding temperature equal to a molding temperature of thefirst resin mold, wherein the second resin mold has Young's modulusequal to or larger than 100 MPa, and wherein the metal plate is bondedto the ceramic substrate via an adhesive.
 15. A manufacturing method ofan electronic device comprising: mounting a first electronic element ona first surface of a ceramic substrate; bonding a metal plate to a firstportion of a second surface of the ceramic substrate, wherein the secondsurface is opposite to the first surface; mounting a second electronicelement on a second portion of the second surface of the ceramicsubstrate, wherein the second portion of the second surface is differentfrom the first portion; sealing the ceramic substrate, the metal plateand the first and second electronic elements with a resin mold; andremoving a portion of the resin mold to expose the metal plate, whereinthe metal plate is bonded to the ceramic substrate via an adhesive. 16.The manufacturing method of claim 13, further comprising: forming aconcavity on the second portion of the second surface of the ceramicsubstrate, wherein the second electronic element is mounted on a bottomof the concavity.
 17. (canceled)
 18. An electronic device comprising: asubstrate that includes a first surface and a second surface opposite tothe first surface; an electronic element disposed in the substrate,wherein the first surface includes a first portion corresponding to theelectronic element; a metal plate bonded to a second surface of thesubstrate so as to expose a second portion of the second surface of thesubstrate opposite to the first portion of the first surface; and aresin mold that seals the first surface of the substrate and seals thesecond surface of the substrate so as to expose the metal plate, whereinthe resin mold sandwiches the first portion of the first surface and thesecond portion of the second surface of the substrate. 19-21. (canceled)22. An electronic device comprising; a ceramic substrate having a firstsurface and a second surface opposite to the first surface; anelectronic element is mounted on the first surface; and a resin moldthat seals the first surface of the ceramic substrate and seals thesecond surface of the ceramic substrate so as to expose an inner portionof the second surface, wherein the first surface has an outer edge, andthe second surface has an outer edge, and wherein the resin moldsandwiches the outer edge of the first surface and the outer edge of thesecond surface.
 23. The electronic device of claim 22, wherein the innerportion of the second surface includes a portion, on which the resinmold covers.
 24. An electronic device comprising: a ceramic substratehaving a first surface and a second surface opposite to the firstsurface; an electronic element mounted on an inner portion of the secondsurface; and a resin mold that seals the first surface of the ceramicsubstrate and seals the second surface of the ceramic substrate so as toexpose the electronic element and the inner portion of the secondsurface, wherein the first surface has an outer edge, and the secondsurface has an outer edge, and wherein the resin mold sandwiches theouter edge of the first surface and the outer edge of the secondsurface.
 25. The electronic device of claim 24, wherein the electronicelement is covered with a protection film.
 26. (canceled)
 27. Amanufacturing method of an electronic device comprising: forming anelectronic element in a substrate, wherein the substrate includes afirst surface and a second surface opposite to the first surface, andthe first surface includes a first portion corresponding to theelectronic element; bonding a metal plate to the second surface of thesubstrate so as to expose a second portion of the second surface of thesubstrate opposite to the first portion of the first surface; andsealing the first surface of the substrate and the second surface of thesubstrate with a resin mold so as to expose the metal plate, wherein theresin mold sandwiches the first portion of the first surface and thesecond portion of the second surface of the substrate. 28-30. (canceled)31. A manufacturing method of an electronic device comprising: mountingan electronic element on a first surface of a ceramic substrate, whereinthe ceramic substrate has the first surface and a second surfaceopposite to the first surface; and sealing the first surface of theceramic substrate and the second surface of the ceramic substrate with aresin mold so as to expose an inner portion of the second surface,wherein the first surface has an outer edge, and the second surface hasan outer edge, and wherein the resin mold sandwiches the outer edge ofthe first surface and the outer edge of the second surface.
 32. Themanufacturing method of claim 31, wherein the inner portion of thesecond surface includes a portion, on which the resin mold covers.
 33. Amanufacturing method of an electronic device including: mounting anelectronic element on an inner portion of a second surface of a ceramicsubstrate, wherein the ceramic substrate has a first surface and thesecond surface opposite to the first surface; sealing the first surfaceof the ceramic substrate and the second surface of the ceramic substratewith a resin mold so as to expose the electronic element and the innerportion of the second surface, wherein the first surface has an outeredge, and the second surface has an outer edge, and wherein the resinmold sandwiches the outer edge of the first surface and the outer edgeof the second surface.
 34. The manufacturing method of claim 33, furthercomprising: covering the electronic element with a protection film afterthe mounting the electronic element.